solve the equations

Question

3x+5y=10, 5x-5y=20$

Answer 1

Given eqations are 3x+5y=10 _______________ (1)

5x-5y=20 ___________ (2)

(1)+(2) ⇒ 3x+5y =10

              5x-5y = 20

           ______________

            8x = 30

              x = 30/8

substitute x in (1)

3(30/8)+5y = 10

90/8+5y = 10

5y = 10-90/8

5y = 80-90/8

5y = -10/8

y = -10/8*5

y = -10/40

y = -1/4

check:

3x+5y = 10

3(30/8)+5(-1/4) = 10

90/8-5/4 = 10

90-10/8 = 10

80/8 = 10

10 = 10