Answer: x-3y+12
Explanation:
You need to know the rules for signed numbers. Study them.
Assuming addition of integers:
Separate your like terms and simply them:
so starting with x terms: -3x+4x ; (4x is the same as saying +4x)
so next with y terms: -2y-y; (remember -y is the same as saying -1y)
so next number with no terms: +7+5
Solve for each: -3x+4x= 1x
-2y-y= -3y
+7+5= 12
Simplify expression with solved termsin order: 1x-3y+12
ans: x -3y +12
Hope this helped.