Question

Solve the systems of equations by substitution.
x = -4y
x + 5y = 2
A. (-8,2)
B. (8,2)
C. (2/9,-8/9)
D. (-12,3)
This is my other question

Answer 1

substitute -4y in the second eq in place of x

Answer 2

I just learned this... Okay @Gagecool Hold on.. I am going to explain this to you.

Answer 3

That gives me the answer 1 Priyar

Answer 4

and okay qwertty123

Answer 5

WELL DONE! thats the correct answer!!

Answer 6

see..its very simple!

Answer 7

But none of the answer choices so a number 1 so i am now confused

Answer 8

The idea here is to solve one of the equations for one of the variables, and plug this into the other equation. It does not matter which equation or which variable you pick. There is no right or wrong choice; the answer will be the same, regardless. But — some choices may be better than others.

Answer 9

hey wait i thought you said option 1

Answer 10

for this class it is is has to be right answer so what do i put when it doesnt have any answer of 1

Answer 11

no i said when i put -4 into the other equation i got the answer 1

Answer 12

@Gagecool he thought you said number one was the answer! :D Miss communication!

Answer 13

\[-4y + 5y =2\] i asked u to plug in -4y!! not 4 coz in the first eq x=-4y

Answer 14

i did i got the answer number 1 when i put -4 into the other equation and added them

Answer 15

oh okay. I am lost but okay! ;)

Answer 16

No put "-4y"

Answer 17

Right priyar i did that and got the answer 1 and it doesn't show in any of the answer choices. i did put - 4y so maybe you can tell what i did wrong

Answer 18

Hey @Gagecool all you really need to know is where the 2 equations intercept!

Answer 19

if you had put -4y then:
\[-4y +5y =2 => y=2\]

Answer 20

Use this calculator to help you! www.desmos.com/calculator

Answer 21

i will do that when i get back i have to go eat some breakfast when i get back you guys need to explain this to me because i still dont get it

Answer 22

now u got y=2 , put y=2 in the first eq :
\[x=-4y => x=-4(2) => x=-8\]

Answer 23

ok.. but first go through all the eq's i have written one by one you will get a better understanding

Answer 24

The easiest way to get this is just finding where they intercept! Here is a calculator!
https://www.desmos.com/calculator Just hover over the two lines where they intercept! That will be your answer. @priyar is also helping you! Great job Priyar! You are doing great I will give you a medal for it! :D

Answer 25

thank u..but @Gagecool must know the algebraic method too..if it comes in exams..