if your friend's doctor wants her target heart rate range to be between 143 and 170, and her average resting heart rate is 62, what us her age? how did you backtrack through these equations to find her age?

The u-drive rent-a-truck company plans to spend $13 million on 320 new vehicles. each commercial van will cost $25 comma 000, each small truck $50 comma 000, and each large truck  $80 comma 000. past experience shows that they need twice as many vans as small trucks. how many of each type of vehicle can they buy?

Solve the system of equations using the substitution method. {y=−3x+7x=−2y−16 enter your answers in the boxes.

What is the answer to this problem? ignore the work. what is the correct answer?