Solve this pls pls pls pls pls

Astudent was asked to find the square of 7x+3. the student quickly wrote (7x+3)^3= 49x^2+9. identify the student's error and provide the correct answer.

Write a function rule for  “the output is  5 less than the input.” let  x be the input and let  y  be the output.

Solve this problem by using a 5d process or writing and solving an equation. no matter which method you use, be sure to define your variable and write an equation to represent the relationship a rectangle has a perimeter of 30 inches. its length is one less than three times its width what are the length and wodyh of the rectangle?