\(-2(4a-9b)=-8a+18b\)

\(-5+(7x-9)=-5+7x-9=7x-14\)

\(-4-(7a-5)=-4-7a+5=-7a+1\)

\(4(2p+7)=8p+28\)

\(-3(-6x+7)+4(-9x+8)=18x-21-36x+32=-18x+11\)

\(5x(2x-6)=10x^2-30x\)

\((2a-7)+(8a+6)=2a-7+8a+6=10a-1\)

\((3x-4)-(5x-2)=3x-4+-5x+2=-2x-2\)

\(5(-8x+6y+9)=-40x+30y+45\)

\((8a+4)(6b+3)=48ab+24a+24b+12\)

\((7a+8)(9a+2)=63a^2+14a+72a+16=63a^2+86a+16\)

\((p+5)(p+9)=p^2+9p+5p+45=p^2+14p+45\)

\((x-9)^2=x^2-18x+81\)

\((4p+9)^2=16p^2+72p+81\)

\((3a-9b)^2=9a^2-54ab+81b^2\)

\((a-7)(a-3)(a-8)=(a-7)(a^2-11a+24)=a^3-11a^2+24a-7a^2+77a-168=a^3-18a^2+101a-168\)

\(x(x-4)(x-5)=x(x^2-9x+20)=x^3-9x^2+20x\)

\((-7p-3q)(-7p+3q)=49p^2-9q^2\)

\((3x-4)(3x+4)=9x^2-16\)

\((a+9)(a-9)=a^2-81\)