Your friend needs to gain weight to wrestle in a heavier weight class. his goal is to gain 2 pounds per week. after 3 weeks, his weight is up to 158 pounds. if the rate of weight gain stays the same, which equation shows his weight at the end of each week? a: y−3=2(x−158) b: y-158=2(x+3) c: y−158=3(x−2) d: y−158=2(x−3)