Question

Solve the system of linear equations by substitution.

y = 2x + 8
y = -2x

Answer 1

Answer:
`y=4,\:x=-2`

Explanation:

`\begin{bmatrix}y=2x+8\\ y=-2x\end{bmatrix}`

`\mathrm{Substitute\:}y=-2x`

`\begin{bmatrix}-2x=2x+8\end{bmatrix}`

`{Isolate\:}x{for -2x=2x+8`

`x=-2`

`\mathrm{For\:}y=-2x`

`\mathrm{Substitute\:}x=-2`

`y=-2\left(-2\right)`

`\mathrm{Simplify}`

`y=4`

`The\:solutions\:to\:the\:system\:of\:equations\:are:`

`y=4,\:x=-2`

Good Luck!

Answer 2

(- 2, 4 )

Explanation:

y = 2x + 8 → (1)

y = - 2x → (2)

substitute y = 2x + 8 into (2)

2x + 8 = - 2x ( add 2x to both sides )

4x + 8 = 0 ( subtract 8 from both sides )

4x = - 8 ( divide both sides by 4 )

x = - 2

substitute x = - 2 into (2)

y = - 2(- 2) = 4

solution is (- 2, 4 )