Question

solve system equations by substitution
x+y=4
-2x-2y=-8

Answer 1

i came up with (3,1)

Answer 2

is that correct

Answer 3

in x+y = 4, minus the x from both sides, so y = 4-x, plug in 4-x into your bottom equation and solve, ... -2x -2(4-x) = -8

Answer 4

once you have your x value, plug that into first equation to get your y

Answer 5

is it (-4,8)

Answer 6

no i still think its (1,3)

Answer 7

the answer is the identity

Answer 8

whats the identity

Answer 9

it's when there is an infinite number of solutions, not just one when you solve the equations by substitution you end up with -8=-8 which is always true

Answer 10

so is it (0,4) for my answer

Answer 11

no the answer is any set of numbers that will work in the first equation, there are an infinite number of answers such as (0, 4), (2,2), (1/2, 3 1/2), (-6, 10) all of these sets will work in the first equation and the second

Answer 12

thanks