Answer:
See below.
Step-by-step explanation:
Let's let the amount of time Melvin spends playing tennis be x, and let's let the time spent swimming y.
He also plays tennis for 40 minutes longer than he swims.
Part A)
He swims and plays tennis for a total of 110 minutes each day. So, we can write the following equation:
We also know that the time spend playing tennis is 40 more than the time spent swimming. Thus:
So, our pair of linear equations are:
Part B)
To find how much time Melvin spends doing each activity every day, we need to solve for our system.
To do so, we can use substitution. Let's substitute the second equation into the first. So:
Combine like terms:
Subtract 40 from both sides:
Divide both sides by 2:
So, Melvin swims for 35 minutes each day (remember that y denotes the time spent swimming, while x denotes the time spent playing tennis!).
Part C)
Since Melvin spent 70 minutes playing tennis, this means that he spent (70-40)=30 minutes playing swimming.
However, 70 minutes of tennis and 30 minutes of swimming only adds up to a total of 100 minutes, 10 minutes shy of our total of 110.
Therefore, it is <em>not</em> possible for Melvin to play only 70 minutes of tennis.