Which expression is equivalent to (x2 − 8) − (−2x2 + 4)?
a) x2 + 12
b) 3x2 + 12
c) −x2 + 12
d) 3x2 − 12

The number of calories you burn depends on your weight. a 110-pound person burns 163 calories during 30 minutes of tennis. find the number of calories that a 190-pound person would burn during the same activity, assuming they burn calories at the same rate.