Two- step equations Algebra 1

Question

If 4y=x+13 and x+2y=5, then x+y=?

Answer 1

Substitution method :

Given  equations are

4y = x + 13  ---> (1)

x + 2y = 5   ---> (2)

From (1) substitute the y value in equation (2).

x + 2(x + 13)/4 = 5

4x + 2x + 26 = 20

6x + 26 = 20

6x = - 6

⇒ x = - 1.

Substitute the x  value in equation (1).

4y = - 1 + 13

y  = 12/4

⇒ y  = 3.

Solution x  = - 1, y  = 3.

Comments

The solution of the given system is x = - 1 and y = 3.

To find x + y, Substitute the values of x = - 1 and y =3.

x + y = - 1 + 3 = 2.

Therefore, x + y = 2.