Question

Which is the equation of a line that passes through the point (3, -4) and has a slope of 2.

Select one:
a. y = 2x - 10
b. y = 2x - 11
c. y = 2x - 4
d. y = 2x - 2

Answer 1

\(\bf \begin{array}{lllll}
&x_1&y_1\\
&({\color{red}{ 3}}\quad ,&{\color{blue}{ -4}})\quad
\end{array}
\\\quad \\

slope = {\color{green}{ m}}= 2
\\ \quad \\

y-{\color{blue}{ y_1}}={\color{green}{ m}}(x-{\color{red}{ x_1}})\qquad \textit{plug in the values and solve for "y"}\\
\qquad \uparrow\\
\textit{point-slope form}\)

Answer 2

the standard straight line equation is

y=mx+b

In th at equation 'm' represents the slope.

The question tells you that the slope is 2 so your equation is

y=2x+b

BUT you know that the point (3,-4) lies on the line

so when y=-4 you know that x= 3

so -4=2*3 +b

Solve for b = and you have oyur answer

Answer 3

is the answer C?

Answer 4

@Twix47
Is that a guess?
Just solve the last equation for the value of b and you have your answer
-4=2*3 +b

Answer 5

@MrNood no i was asking if i was right?

Answer 6

if you are not right - are you then going to go
'is it d'
'is it a'
'is it b'

Try to solve the equation by following the help given above.

Answer 7

no im not dang but 2*3=6 so it would then look like -4=6+b so actually wouldnt it be D because 6-4=2 so it would look like y=2x-2

Answer 8

so far you ar correct that 2*3 =6

SO the equation is -4= 6+b

You need to solve that correctly for the value of b

Answer 9

but what is b?

Answer 10

the equation for any straight line is
y=mx+b

m is the slope (which oyu know is 2)

so your answer is in the form
y=2x+b

BUT you know that the point ( 3,-4) is on the line SO when y=-4 you know x=3

SO -4=2*3+b

Work out what b is from the above equation

then you have your answer:

y=2x+b

Answer 11

i got y=2x-4

Answer 12

you know that when y=-4 then x = 3

Does your equation work for that point?

i.e. does -4=2*3 - 4

If not then your answer is wrong

Answer 13

PLEASE try to solve this equation

-4=2*3+b

Work out what b is from the above equation

then you have your answer:

y=2x+b

Answer 14

-4=6-4 so it would be D y=2x-2

Answer 15

you know that when y=-4 then x = 3

Does your equation work for that point?

i.e. does -4=2*3 - 2
If not then your answer is wrong