a) \(7x^2+34x-5=7x\left(x+5\right)-1\left(x+5\right)\)
\(=\left(x+5\right)\left(7x-1\right)\)
b) \(12a^2-3ab+8ac-2bc=3a\left(4a-b\right)+2c\left(4a-b\right)\)
\(=\left(4a-b\right)\left(3a+2c\right)\)
\(a,=7x^2-x+35x-5=x\left(7x-1\right)+5\left(7x-1\right)=\left(x+5\right)\left(7x-1\right)\\ b,=3a\left(4a-b\right)+2c\left(4a-b\right)=\left(3a+2c\right)\left(4a-b\right)\)
Phân tích đa thức thành phân tử:
a) 7x2+34x−5
=7x(x+5)−1(x+5)
=(x+5)(7x−1)
b) 12a2−3ab+8ac−2bc
=3a(4a−b)+2c(4a−b)
=(4a−b)(3a+2c)
