Question

Peter's weight is 12 pounds more than twice

Susan's weight. Find Peter's weight if together
they weigh 150 pounds.

Answer 1

81 pounds.

Explanation:

Let p represent Peter's weight, in pounds

Let s represent Susan's weight, in pounds

p = s + 12

p + s = 150

Now you can substitute the first equation into the second one.

s + 12 + s = 150

2s + 12 = 150

2s = 138

2s/2 = 138/2

s = 69

Since we know Peter's weight is 12 pounds heavier than Susan, and now that we also know Susan's weight, we can just add 12 pounds to Susan's weight or we can just plug it into the first equation.

p = 69 + 12

p = 81