Theo's overall change is $21 because since they are different signs of adding integers, you subtract the absolute value of the greatest to the least and the higher absolute value u use the same sign as
<span>X= math problems
y= science problems
x +y =42
x= y+10
Substitute: (y+10) + y =42
Combine y: 2y +10=42
Solve for y: y= 16
There are 16 science questions and 26 math questions</span>
