Question

Twice a number plus twice a second number is 310. The difference between the numbers is 55. Find the numbers by writing and solving a system of equations.

Answer 1

2x+2y=310
x-y=55
multiply seond equation by 2 and adding to first equation

2x-2y=110
add

2x-2y=110
2x+2y=310 +
4x+0y=420

4x=420
divide 4
x=105
sub
x-y=55
105-y=55
minuse 105
-y=-50
mult -1
y=50

the numbers are 105 and 50