\(B=x^3-9x^2+27x-27\)
\(B=\left(x-3\right)\left(x^2+3x+9\right)-9x\left(x-3\right)\)
\(B=\left(x-3\right)\left(x^2-6x+9\right)\)
\(B=\left(x-3\right)\left(x-3\right)^2\)
\(B=\left(x-3\right)^3\)
Thay x = 13 vào, có:
\(B=\left(13-3\right)^3=10^3=1000\)
\(A=x^3+15x^2+75x+125\)
\(A=\left(x+5\right)\left(x^2+5x+25\right)+15x\left(5+x\right)\)
\(A=\left(x+5\right)\left(x^2+6x+30\right)\)
Thay x=-10, ta có:
\(A=\left(5-10\right)\left[\left(-10\right)^2+6.\left(-10\right)+30\right]\)
\(A=-5.70\)
\(A=-350\)
a)=-350
b)=1000
còn câu C thì mình đang nghĩ