Question

solve the system by substitution. Give the x - value of the solution. y-4x=0 and x=-15+4y

Answer 1

Substitution method

y-4x = 0

Add 4x to each side.

y-4x+4x = 0+4x

y = 4x -------> (1)

x = -15+4y

From (1) substitute the y value in above equation.

x = -15+4*4x

x = -15+16x

Subtract 16x from each sode.

x-16x = -15+16x-16x

-15x = -15

Divide to each side by negitive 15.

-15x/-15 = -15/-15

⇒ x = 1

Substitute the x value in (1).

y =4*1

⇒ y = 4

Solution x = 1, y = 4.