Solve the system of equations by substitution method. Y=3x+7. y=5x+8

x = y = 5.5

Step-by-step explanation:

substitution method

3x + 7 = 5x + 8

subtract 3x from both sides

7 = 2x + 8

subtract 8 from both sides

-1 = 2x

divide each side by 2

x =

substitute the x in either equation

y = 3(-1/2) + 7

y = -1.5 + 7

y = 5.5

or

y = 5(-1/2) + 8

y = -2.5 + 8

y = 5.5

option 3 . (5x + 1) - (-10x + 6)

step-by-step explanation:

option 1 :

(4x + 3) + (-9x + 4)

or 4x+3 -9x + 4

or -5x + 7

option 2

(x - 2) - (6x - 9)

or x-2-6x + 9

or -5x + 7

option 3

(5x+ + 6)

or 5x + 1 + 10x -6

or 15x -5

option 4

-4x+2x+7-3x

-7x + 2x + 7

-5x + 7

hence only option 3 did   not satisfy the given simplify expression.