Question

xy-5x    b 2xy+x^2-16+y^2         c) a^2 -ac-9b^2+3bc

Answer 1

\(xy-5x=x(y-5)\)

\(b)2xy+x^2-16+y^2=x^2-2xy+y^2-16=(x-y)^2-16=(x-y)^2-4^2=(x-y-4)(x-y+4\)

\(c)a^2-ac-9b^2+3bc=a(a-c)-3b(b-c)=(a-c(b-c)(a-3b)\)

Answer 2

a)

\(=x\left(y-5\right)\)

b)

\(2xy+y^2-16+y^2=\left(x+y\right)^2-4^2=\left(x+y+4\right)\left(x+y-4\right)\)

c)

\(a^2-ac-9b^2+3bc=\left(a^2-9b^2\right)-\left(ac-3bc\right)=\left(a-3b\right)\left(a+3b\right)-c\left(a-3b\right)=\left(a-3b\right)\left(a+3b-c\right)\)

Answer 3