Answer:
y = 15
x = 43
Explanation:
this is giving us a system of equations because we know two things:
x + y = 58
x - y = 28
take the second equation and format it where you have simplified it for one variable:
x = 28 + y
(we did this by adding y to both sides)
now substitute this new value of x into the first equation:
28 + y + y = 58
simplify this to get 2y = 30
divide both sides by 2: y = 15
now substitute your new value of y into the second equation:
x = 28 + 15
x = 43