Question

At the gym, Cara burns 12 calories per minute on the elliptical and 10 calories per minute on the treadmill. If she worked out for one hour and burned 676 calories, how many minutes did she spend on the elliptical

Answer 1

E=elliptical
T= treadmill
12E+10T=676
also, she worked out one hour
E+T=60
E=60-T   we substitute now
12(60-T)+10T=676
720-12T+10T=676
720-2T=676  substract 720 from both sides
-2T=-44 now divide by (-2)
T=22
if T=22 E=60-22=38
she spends 38 min on the elliptical