Help with question three please :)

Write the expression 7x^3-28xy^2 as the product of 3 factors

Y=21.95x+10 y=22.45x solve by substitution

Urgent? will give brainliest given that the blue triangle is a right triangle, which expression correctly gives the area of the red square? a) a2 + b2 b) a2 - b2 c) a2 - c2 d) c2 - a2