Question

Solve 2x + y = 7
x – y = –4, please help, Its easy I just forgot exactly what to do

Answer 1

solve for x and y
either by using the elimination method, or gaussian elimination, or substitution, or etc

Answer 2

you can let x = y -4 then use substitution for x in the first equation

Answer 3

do I need to multiply by the reciprocal to eliminate?

Answer 4

no, you can just add both equations, and the y's will cancel

Answer 5

so 2x^2=3?

Answer 6

okay thank you :)

Answer 7

2x + x = 3x

Answer 8

3x = 3
x = 1

Answer 9

alright you just solved and got 3 then substituted right ?

Answer 10

x = 1, not 3, i made a mistake

now you can substitute x = 1 in for the bottom equation

1 - y = -4

solve for y

Answer 11

so 5 and 1

Answer 12

-5

Answer 13

yes, x = 1
y = 5

you can put them back into either equation to check your work

Answer 14

something is off wouldnt need to be 1-(-5) = -4 ?

Answer 15

no, y = 5

1 - (5) = - 4
-4 = -4

Answer 16

oh okay

Answer 17

I got it now thanks a lot :D