Question

3.Giải phương trình tích:

a) (x-1)+(2x+10)=0

b) 2x (x - 5 ) +3 ( x - 5 ) = 0

c) 4x ( x - 3 ) - 5x + 15 = 0

d) x² - x - 3 (x-1)=0

e) x² - 9x =0

Answer 1

https://i.imgur.com/FJ5ecBX.jpg

Answer 2

a, (x - 1) + (2x + 10 ) = 0

=> x - 1 + 2x + 10 = 0

=> ( x + 2x ) - ( 1 - 10 ) = 0

=> 3x + 9 = 0

=> 3x = -9

=> x = -9 : 3

=> x = -3

b, 2x.(x - 5) +3.(x-5) = 0

=> ( 2x + 3).(x - 5) = 0

=> 2x + 3 =0 hoặc x - 5 = 0

=> 2x = -3 x = 5

=> x = \(\frac{-3}{2}\) x = 5

c, 4x.( x - 3) - 5x + 15 =0

=> 4x .(x - 3) - 5.(x -3 ) = 0

=> ( 4x - 5).(x - 3) =0

=> 4x - 5 = 0 hoặc x - 3 = 0

=> 4x = 5 x = 3

=> x = \(\frac{5}{4}\) x = 3

d, \(x^2-x-3\left(x-1\right)=0\)

=> x.(x - 1) - 3.(x - 1) = 0

=> (x - 3). (x -1 ) = 0

=> x - 3 = 0 hoặc x - 1 = 0

=> x = 3 x = 1

e, \(x^2-9x=0\)

=> x.(x - 9) = 0

=> x = 0 hoặc x - 9 =0

=> x = 0 x = 9