solve the system of the equations 2x + 3y = 40 and -2x + 2y = 20.

Question

algebra hw please help solve i  need this answer . thanks!!

Answer 1

Elimination method :

The equations are

2x + 3y = 40    ---------------->(1)

-2x + 2y = 20   ---------------->(2)

Add (1) & (2).

2x + 3y = 40

-2x + 2y = 20
-     +.       +

__________

5y = 60

=>y = 60/5 = 12.

Substitute the values y = 12 in (1).

2x + 3(12) = 40

2x +36 = 40

2x = 40 - 36 = 4

2x = 4

=>x = 2.

The solution of the system is x = 2 and y = 12.