Question

Answer 1

c: =(x-8)(x+5)

b: =(x+3-5y)(x+3+5y)

Answer 2

\(b,x^2+6x-25y^2+9=\left(x^2+6x+9\right)-25y^2=\left(x+3\right)^2-\left(5y\right)^2=\left(x-5y+3\right)\left(x+5y+3\right)\\ c,x^2-3x-40=\left(x^2+5x\right)-\left(8x+40\right)=x\left(x+5\right)-8\left(x+5\right)=\left(x+5\right)\left(x-8\right)\)