5 questions for algebra please help!!!
where are the questions one by one
1.What is the slope of the line that passes through the pair points (-7/2,-3) and (-5,5/2) a.6/22 b.-6/22 c.22/6 d-22/6 2.tell whether the lines for each pair of equations are parallel,perpendicular,or niether Y=-3x+7 -2x+6y=3 a.parallel b.perpendiclar c.neither 3.tell whether the lines for each pair of equations are parallel,perpendicular,or neither Y=-1/4x+10 -2x+8y=6 a.parallel b.perpendicular c.neither 4. the table shows the number of miles driven over time. Time(hours)|distance(miles) 4 232 6 348 8 464 10 580 Express the relashionship between distance and time in simplified form as a unit rate. Determine which statement correctly interprets this relashionship. a. 232; your care travels 232 miles. b. 1/58; your car travels 58 miles in 1 hour. c. 58/1; your car travels 58 miles in 1 hour d. 1/10; your car travels for 10 hours 5. For the data in the table, does y vary directly with x? if it does write an equation for the direct variation. X | Y 10 12 15 18 20 24 a. Yes; y=1.2x b. Yes; y=2x c. Yes; y=x+1
@dayakar
hint: the slope \(m\) of a line which passes at points: \[\left( {{x_1},{y_1}} \right),\quad \left( {{x_2},{y_2}} \right)\] is given by the subsequent formula: \[m = \frac{{{y_2} - {y_1}}}{{{x_2} - {x_1}}}\]
Yea i know the slope formula but when i did it i got none of the anwsers so im confused
let's suppose this: \[\left( {{x_1},{y_1}} \right) = \left( { - 5,5/2} \right),\quad \left( {{x_2},{y_2}} \right) = \left( { - 7/2, - 3} \right)\]
so -7/2-(-5)/-3-5/2 right?
then after a simple substitution, we get: \[\huge \begin{gathered} m = \frac{{{y_2} - {y_1}}}{{{x_2} - {x_1}}} = \frac{{ - 3 - \frac{5}{2}}}{{ - \frac{7}{2} - \left( { - 5} \right)}} = \hfill \\ \hfill \\ = \frac{{\frac{{\left( {\left( { - 3} \right) \cdot 2} \right) - 5}}{2}}}{{\frac{{ - 7 + \left( {5 \cdot 2} \right)}}{2}}} = ...? \hfill \\ \end{gathered} \]
i got -5 1/2/1 1/2
that's right!
such result can be rewritten as follows: \[\huge \begin{gathered} m = \frac{{{y_2} - {y_1}}}{{{x_2} - {x_1}}} = \frac{{ - 3 - \frac{5}{2}}}{{ - \frac{7}{2} - \left( { - 5} \right)}} = \hfill \\ \hfill \\ = \frac{{\frac{{\left( {\left( { - 3} \right) \cdot 2} \right) - 5}}{2}}}{{\frac{{ - 7 + \left( {5 \cdot 2} \right)}}{2}}} = \frac{{ - \frac{{11}}{2}}}{{\frac{3}{2}}} \hfill \\ \end{gathered} \]
now, please multiply both numerator and denominator, of last side, by \(4\)
it would be -22/6 right?
|dw:1451151409620:dw| that's right!
Can you help me with number 2?
second question: two lines, for example: \(y=m_1x+q_1\) and \(y=m_2x+q_2\) are parallel if \(m_1=m_2\)
so is number 2 perpendicular
we have this: the first line is \(y=-3x+7\), so the first slope is \(m_1=-3\) whereas the second line is \(y=(1/3)x+1/2\) so the second slope is \(m_2=1/3\)
now, please what is the product: \(m_1 \times m_2=...?\)
m1=1/2 m2 m2=1/2 so they have the same y intercept correct?
for #2 you have to put both equations in slope intercept for and if they have the same y intersept then it perp if it has the same slope its par.
so im correct the second one is perpendicular because it has the same slope just reciprocal of each other and the y intercept is the same?
hint: we can write this: \[\huge {m_1} \times {m_2} = \frac{1}{3} \times \left( { - 3} \right) = ...?\]
-1
that's right they are perpendicular. Nevertheless the y-intercept of the first line is 7, whereas the y-intercept of the second line is 1/2
and im guessing number 3 is paralell
i think number 3 is parallel because the slopes are the same but the y intercepts are different am i wrong?
we can rewrite the second equation as below: \(y=(1/4)x+3/4\) so the slope of the second line is \(1/4\), whereas the slope of the first line is \(-1/4\)
now we can see that: \(m_1\) is different from \(m_2\), furthermore \(m_1 \times m_2=-1/16\), so what can you conclude?
paralell
are you sure? parallel lines have the same slope
ohh so it would be neither
that's right!
i didnt see the negative sign for the second slope ;)
ok! :)
now, for the fourth exercise, we can see that the ratio: \[\frac{{{\text{distance}}}}{{{\text{time}}}}\] is constant for each ordered pair. Please what is the value of such constant?
namely, please compute these ratios: \[\Large \begin{gathered} \frac{{232}}{4} = ...? \hfill \\ \hfill \\ \frac{{348}}{6} = ...? \hfill \\ \hfill \\ \frac{{464}}{8} = ...? \hfill \\ \hfill \\ \frac{{580}}{{10}} = ...? \hfill \\ \end{gathered} \]
they all equal 58
so the anwser is.... 58/1 or 1/58 i got confused on that
yes! correct! so the requested relation is: \[\large \frac{{{\text{distance}}}}{{{\text{time}}}} = 58\] or: \[\large {\text{distance}} = 58 \times {\text{time}}\]
now, if \(time = 1\) hour, what is the \(distance\)? \[\large {\text{distance}} = 58 \times {\text{time}} = 58 \times 1 = ...?\]
58/1
that's right!
for 5 im really confused
im not good at direct variations
5. For the data in the table, does y vary directly with x? if it does write an equation for the direct variation. X | Y 10 12 15 18 20 24 a. Yes; y=1.2x b. Yes; y=2x c. Yes; y=x+1 d. No; ydoes not vary directly with x.
hint: again please compute these ratios: \[\huge \begin{gathered} \frac{{12}}{{10}} = ...? \hfill \\ \hfill \\ \frac{{18}}{{15}} = ...? \hfill \\ \hfill \\ \frac{{24}}{{20}} = ...? \hfill \\ \end{gathered} \]
oooooh 1.2 so ye=1.2x
that's right!
Thanks ;) you are a really good helper
:)
can i ask you another question? @Michele_Laino
ok!
For the data in the table does y vary directly with x? if it does, write an equation for the direct variation X | Y 40 32 28 16 16 12 a. Yes; y=2x b. Yes; y= 0.5x c. Yes’ y=1.5x d. No; y does not vary directly with x
@Michele_Laino
Desribe how the graphs of y=|x| and y=|x+5| are related a. The graphs have the same shape. The y intercept of y=|x| is 0 and the y intercept of the second graph is 5 b. The graphs have the same shape. The y intercept of y =|x| is 0 and the y intercept of the second graph is -5 c. The two graphs are the same. d. The graphs have the same shape. The y intercept of y=|x| is 0 and the x intercept if the second graph is 5
Desribe how the graphs of y=|x| and y=|x|-5 are related a. The graphs have the same shape. The y intercept of y=|x| is 0 and the y intercept of the second function is 5 b. the functions have the same y intercept. The second function is steeper tha y=|x| c. The two functions are the same. d. The graphs have the same shape. The y intercept of y=|x| is 0 and the x intercept if the second function is - 5
For the first one, i would suggest multiplying your x's in to your equations.
i think it is D
it doesnt vary directly with x @Lovelarap
yup
as we can see the y-coordinate of the graph \(y=|x|-5\) is 5 points less than the corresponding graph \(y=|x|\)
for the last two, try this document:
so my anwser is d. The graphs have the same shape. The y intercept of y=|x| is 0 and the x intercept if the second function is - 5
that's right! I think that in your textbook there is a typo, since the correct statement is: The graphs have the same shape. The y intercept of y=|x| is 0 and the \(y\) intercept if the second function is - 5
oh i wrote it wrong it said y intercept
ok! :) it is option d
and for Desribe how the graphs of y=|x| and y=|x|-5 are related a. The graphs have the same shape. The y intercept of y=|x| is 0 and the y intercept of the second graph is 5 b. the functions have the same y intercept. The second functions is steeper tha y|x| c. The two graphs are the same. d. The graphs have the same shape. The y intercept of y=|x| is 0 and the x intercept if the second graph is 5 my anwser is either a or d but im not sure
oops i ment y=|x| and y=|x+5| are related
a. The graphs have the same shape. The y intercept of y=|x| is 0 and the y intercept of the second graph is 5 b. The graphs have the same shape. The y intercept of y =|x| is 0 and the y intercept of the second graph is -5 c. the two graphs are the same. d. The two graphs are the same. d. The graphs have the same shape. The y intercept of y=|x| is 0 and the x intercept if the second graph is 5
in order to find the y.intercept, we have to replace \(x=0\). So the y-intercept of the first graph,is: \(y=|x|=|0|=...?\) whereas the y-intercept of the second graph is: \(y=|x+5|=|0+5|=...?\)
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