Question

Write your answer as a x,y pair. 2x+3y=7. Y=2x-11 Solve using the SUBSTITUTION METHOD

Answer 1

(5, -1) or x = 5, y = -1

Explanation:

`\mathrm{Substitute\:}y=2x-11`

`\begin{bmatrix}2x+3\left(2x-11\right)=7\end{bmatrix}`

`8x-33=7`

`\mathrm{Isolate}\:x\:\mathrm{for}\:8x-33=7`

`8x=40`

`\mathrm{Divide\:both\:sides\:by\:}8`

`(8x)/(8)=(40)/(8)`

`x=5`

`y= 2x-11 \\ \mathrm{Substitute\:}x=5`

`y=2\cdot \:5-11`

`y=-1`

Answer 2

(5, - 1 )

Explanation:

2x + 3y = 7 → (1)

y = 2x - 11 → (2)

substitute y = 2x - 11 into (1)

2x + 3(2x - 11) = 7

2x + 6x - 33 = 7

8x - 33 = 7 ( add 33 to both sides )

8x = 40 ( divide both sides by 8 )

x = 5

substitute x = 5 into (2)

y = 2(5) - 11 = 10 - 11 = - 1

solution is (5, - 1 )