Question

Làm tính nhân

a) (x² + 8x - 3)(x + 2)

b)10x²(9x³ + 4x + 3) + (x + 9)²

Answer 1

\(a.\left(x^2+8x-3\right)\left(x+2\right)=x^3+8x^2-3x+2x^2+16x-6=x^3+10x^2+13x-6\)

\(b.10x^2\left(9x^3+4x+3\right)+\left(x+9\right)^2\)

\(=90x^5+40x^3+30x^2+x^2+18x+9^2=90x^5+40x^3+31x^2+18x+81\)

Answer 2

a, ( x² + 8x - 3 )( x + 2) = x³ + 2x² + 8x² + 16x - 3x - 6

= x³ + 10x² + 13x - 6

b, 10x²(9x³ + 4x + 3) + (x + 9 )² = 90x⁵ + 40x³ + 30x² + x² + 18x + 81

= 90x⁵ + 40x³ + 31x² + 18x + 81

Answer 3

nhớ rút gọn biểu thúc nhé!