Question

Solve:
x+y=5
x-4y=20

Answer 1

x=8

y=-3

Explanation:

let

x+y=5........ equation 1

x-4y=20....... equation 2

x=20+4y

substituting the value of x in eq 1

x+y=5

20+4y+y=5

5y=5-20

y=-15/5

y=-3

again putting the value of y in eq 2

x=20+4y

x=20+4(-3)

x=20-12

x=8