Question

Bài 1: Thực hiện phép tính:
a) 2x.(3x + 3) b) 5x.(3x²-2x + 1) c) 3x²(2x +4)

d) 5x².(3x2 + 4x – 1) e) (x-1).(2x +3) f) (x+2).(3x-5)

Bài 2: Tìm x, biết:

a) 3x(x+1) – 3x² = 6

b) 3x(2x+1) – (3x +1).(2x-3) = 10

Answer 1

Bài 1:

\(a,=6x^2+6x\\ b,=15x^3-10x^2+5x\\ c,=6x^3+12x^2\\ d,=15x^4+20x^3-5x^2\\ e,=2x^2+3x-2x-3=2x^2+x-3\\ f,=3x^2-5x+6x-10=3x^2+x-10\)

Bài 2:

\(a,\Leftrightarrow3x^2+3x-3x^2=6\\ \Leftrightarrow3x=6\Leftrightarrow x=2\\ b,\Leftrightarrow6x^2+3x-6x^2+9x-2x-3=10\\ \Leftrightarrow10x=13\Leftrightarrow x=\dfrac{13}{10}\)