Đây là nhân đa thức nha . Tìm hộ mik với
Tìm x biết:
a) 3x(8x – 4) – 6x(4x – 3) = 30
b) (12x – 5)(4x – 1) + (3x – 7)(1 – 16x) = 18
c) (2x + 3)(x – 4) – 3x(x – 1) + (x – 5)(x – 2) + 5x = 2
Đây là nhân đa thức nha . Tìm hộ mik với Tìm x biết: a) 3x(8x – 4) – 6x(4x – 3) = 30 b) (12x – 5)(4x – 1) + (3x – 7)(1 – 16x) = 18 c) (2x + 3)(x –
By Adeline
`a)3x(8x-4)-6x(4x-3)=30`
`⇔24x²-12x-24x²+18x=30`
`⇔6x=30`
`⇔x=5`
Vậy `x=5`
`b)(12x-5)(4x-1)+(3x-7)(1-16x)=18`
`⇔48x²-12x-20x+5+3x-48x²-7+112x=18`
`⇔83x-2=18`
`⇔83x=20`
`⇔x=20/83`
Vậy `x=20/83`
`c)(2x+3)(x-4)-3x(x-1)+(x-5)(x-2)+5x=2`
`⇔2x²-8x+3x-12-3x²+3x+x²-2x-5x+10+5x=2`
`⇔-4x-2=2`
`⇔-4x=4`
`⇔x=-1`
Vậy `x=-1`
`a) 3x (8x-4) – 6x(4x-3) =30`
`=> 24x^2 – 12x – 24x^2 + 18x = 30`
`=> 6x = 30`
`=> x = 30 :6`
`=> x = 5`
Vậy `x=5`
`b) (12x – 5)(4x-1) + (3x-7)(1-16x) = 18`
`=> 48x^2 -12x – 20x+5 + 3x-48x^2 – 7 + 112x =18`
`=> 83x -2 = 18`
`=> 83x = 20`
`=> x = 20/83`
Vậy `x=20/83`
`c) (2x+3)(x-4) – 3x(x-1) + (x-5)(x-2) +5x=2`
`=> 2x^2 – 8x + 3x-12- 3x^2 + 3x + x^2 – 2x – 5x + 10 + 5x=2`
`=> -4x-2 = 2`
`=> -4x= 4`
`=> x = -1`
Vậy `x=-1`