Please help i dont understand this.

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.

The perimiter of a rectangle is 70 inches the legneth of the rectangle is 5 less than 3 times the width of the rectangle what is the width of the rectangle

15/16 as a decimal rounded to the nearest hundredth