Help , for a math test .

Are carpet coast $15 per square metre. the total delivery charge is $21 peter buys n squared metres of carpet what is the expression which represents the total cost in $

Amonument at a park is in the shape of a right square pyramid. a diagram of the pyramid and its net are shown. what is the surface area of the monument? enter the answer in the box. m²

X2 + y 2 = 36 x + y = 6 solve the system of equations.