can you please help me with my math homework

THINKING 10. There is a house in the middle of a rectangle lot. The shaded area represents the grass around the house. To find the area of sod required, you need to find the area of the shaded portion. A student said the area could be found using the expression(x + 10) (5x + 2) + (x) (2x). a) What error did the student make? [1 mark] b) Fix the error and expand and simplify the expression. [5 marks] House 2x 2 + Xg X x + 10 c) The class was asked to find the area if x = 4 metres. Matilda says: "Sub in the 4 after you have expanded and simplified the algebraic expression." Henrietta says: "Sub in the 4 before you expand and simplify." Gertrude says: "Sub in the 4 on the diagram first and then calculate the area." Matilda, Henrietta and Gertrude all got the right answer. Explain why. [2 marks]