Question

thực hiện phép tính :
a) 2.(x-1)² -4.(3+x)²+2x.(x-5)
b) 2.(2x+5)²-3.(4x+1).(1-4x)
Giúp mình với ạ

Answer 1

a) 2(x-1)² - 4(x+3)² + 2x(x-5)

= 2(x² -2x +1)- 4(x² + 6x +9) + 2x² -10x

= 2x² - 4x + 2 -4x² - 24x - 36 + 2x² - 10x

= (2x² + 2x² - 4x²) - (4x + 24x+10x) +(2-36)

= -38x-34

b) 2(2x+5)²  -3(4x+1)(1-4x)

= 2(4x² + 20x + 25) + 3(4x+1)(4x-1)

= 8x² +40x + 50 + 3(16x² -1)

= 8x² + 40x + 50 + 48x² - 3

=56x² +40x + 47

Answer 2

a, \(2\left(x-1\right)^2-4\left(x+3\right)^2+2x\left(x-5\right)\)

\(=2\left(x^2-2x+1\right)-4\left(x^2+6x+9\right)+2x\left(x-5\right)\)

\(=2x^2-4x+2-4x^2-24x-36+2x^2-10=-28x-44\)

b, \(2\left(2x+5\right)^2-3\left(4x+1\right)\left(1-4x\right)\)

\(=2\left(4x^2+20x+25\right)-3\left(1-16x^2\right)\)

\(=8x^2+40x+50-3+48x^2=56x^2+40x+47\)

Answer 3

mình sửa dòng cuối phần a nhé 

\(=2x^2-4x+2-4x^2-24x-36+2x^2-10x=-38x-34\)

Answer 4

2.(x-1)^2 - 4.(3+x)^2 + 2x.(x-5) 

= 2.( x^2 - 2x + 1 ) - 4.( 9 + 6x + x^2 ) + 2x^2 - 10x 

= 2x^2 - 4x + 2 - 36 - 24x - 4x^2 + 2x^2 - 10x 

= - 38x - 34 

Answer 5

2.(2x+5)^2 - 3.(4x+1).(1-4x) 

= 2.(4x^2+20x+25) - 3.(1-16x^2) 

= 8x^2 + 40x + 50 - 3 + 48x^2 

= 56x^2 + 40x + 47 

Answer 6

4.(x+1)^2+(2x-1)^2-8(x-1).(x+1)