In the system of equations above, a and b represent the distance, in meters, two marathon runners are…

a = 4800 – 6t
b = 5400 – 8t

In the system of equations above, a and b represent the distance, in meters, two marathon runners are from the finish line after running for four hours and t seconds. How far will runner a be from the finish line when runner b passes her?

A. 300 meters
B. 500 meters
C. 100 meters
D. 3000 meters

A tank initially contains 7 gallons of water. A faucet is opened and water begins pouring into the tank at a rate of 1.5 gallons per minute until the tank is full.

A tank initially contains 7 gallons of water. A faucet is opened and water begins pouring into the tank at a rate of 1.5 gallons per minute until the tank is full. Which of the following represents the volume V of water in gallons in the tank as a function of time t in minutes that has elapsed since the faucet is opened?

A) v(t)=1.5+t
B)v(t)=8.5+t
C)v(t)=1.5t
D)v(t)=1.5t-7
E)v(t)=1.5t+7
Thanks

Solving systems of linear equations

The new SAT places a heavy emphasis on the “Heart of Algebra,” which is a bizarre and tortured euphemism for, mostly, working with linear equations. One of the kinds of questions you know you’re going to see, probably more than once, on your SAT is solving systems of linear equations. For example: Which ordered pair satisfies (more…)