Question

Solutions to this equation:
4x+5y=20
x+y=1

Answer 1

Multiply the second equation by either 4 or 5 and subtract it from the first equation to eliminate one of the variables x or y , then solve....

so if I multiply Eq2 by 4 it becomes 4x+4y=4

subtract this from Eq1 to eliminate x gives
4x-4x+5y-4y=20-4
y=16

so to solve for x substitue y =16 in Eq2
x + 16=1; therefore x=-15