I need to know what goes in the amount & interest box and why

What is the equation and solution for the sentence? the sum of a number and thirty-one is one hundred thirteen. write the equation as n-31=113 and subtract 31 from both sides. the answer is 82. write the equation as n+31=113 and subtract 31 from both sides. the answer is 82. write the equation as n+31=113 and add 31 to both sides. the answer is 144. write the equation as n-31=113 and add 31 to both sides. the answer is 144.

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.

If f(x)=x+7 and g(x)=1/x what is (fog)(x)