Question

Help Please :)
http://prntscr.com/92ni5u

Answer 1

actually you don't need to draw graphs. you can substitute given x value in 2 equation and select the system gives same value for both y.

Answer 2

? Im confused

Answer 3

well, take first system
y = x^2
y = 4x + 2

and we are given x = -0.4

now put that value in those two equations
y = (-0.4)^2 = 0.16
y = 4(-0.4) + 2 = 0.4

Answer 4

see, y values are not same. that means x = -0.4 is not a solution for 2 equations.

Answer 5

so first one is not an answer

Answer 6

so first one is not an answer

Answer 7

get it?

Answer 8

So would it be C?

Answer 9

yes. you are correct:)

Answer 10

Thank you,Do uu think you coul help me with two more diffucult problems please?

Answer 11

sure

Answer 12

Thank youu !:D Okaii Before we start are these two correct?
http://prntscr.com/92notk

Answer 13

first one is not right.

Answer 14

you want to put x value of pairs in equations and see y comes up

Answer 15

same thing like before

Answer 16

So the first is A?

Answer 17

take (-1,2)

y = x^2 + 1
y = 3x -1

now take x value of (-1,2). that is x = -1. now put in equations

y = (-1)^2 + 1 = 2
y = 3(-1) -1 = -4

(-1,2) is not an answer because y is not 2 for both equations

Answer 18

try others like that. there is one solution. I can see it:)

Answer 19

Wait would it be B? Since Y isnt 2 for both sides

Answer 20

not B. (-1,2) doesn't work here. you don't get y = 2 from second equation:(

Answer 21

Okaiii Sorry I was inserting it wrong,Its c..Okaii heres the last one
http://prntscr.com/92ntm7

Answer 22

yes c is the answer.

well, you know already the highest point of B. right?

Answer 23

Yes :D

Answer 24

you say it from the graph

Answer 25

@lochana is correct c is the right answer

Answer 26

yeah. now we have A(t) = -(t-10)^2 + 455 (A rocket)

here (t - 10)^2 is always positive right ?

Answer 27

it is a square of a number

Answer 28

Is the answer A? :D

Answer 29

no:)

Answer 30

Oh :( Sorry

Answer 31

yeah. what i wanted to say the fact that
A(t) = -(t-10)^2 + 455 is takes highest value of A(t) when t = 10

Answer 32

So its C?

Answer 33

noo:(. not A.:(

Answer 34

not A rocket

Answer 35

Im so confused

Answer 36

yes. that's because you don't get the highest value of A(t) = -(t-10)^2 + 455

Answer 37

tell me what must happen to (t-10)^2 to make A(t) highest?

Answer 38

it has to be solved

Answer 39

no. there is a tricky part.

Answer 40

can you understand that -(t-10)^2 is always negative??

Answer 41

because (t- 10)^2 is always positive. it is a square of a number. squares are never become negative:)

Answer 42

so is (t-10)^2 is postive, then -(t-10)^2 is always negative

Answer 43

if you understand that. this question is solved

Answer 44

I dont understand

Answer 45

5^2 is positive. right?

Answer 46

\(5^2 = +25\)

Answer 47

right?

Answer 48

Yes

Answer 49

so
\((-5)^2 = +25\)
\((t-10)^2 = positive\)

Answer 50

the key point is that whatever the number be, when you square it, it become positive value

Answer 51

t -10 is also a number. just like +5, -5

Answer 52

don't think about the actual value of (t-10)^2. think about sign of it. it is always positive.there is no way ,you get negative values from squaring.

Answer 53

are you still lost:'(

Answer 54

So the answers B?,Im still kind of lost