Question

(3x²-2x+5)-(x²+4x²-x-7)

4(2x+1)-5(3x+2)

Answer 1

a) Ta có: \(\left(3x^2-2x+5\right)-\left(x^2+4x^2-x-7\right)\)

\(=3x^2-2x+5-5x^2+x+7\)

\(=-2x^2-x+12\)

b) Ta có: \(4\left(2x+1\right)-5\left(3x+2\right)\)

\(=8x+4-15x-10\)

=-7x-6

Answer 2

hai câu khác nhau,đừng nhầm lẫn

Answer 3

 

(3x²-2x+5)-(x²+4x²-x-7)

=3x^2 -2x+5-x^2+4x^2-x-7

=6x^2-3x-2

 

Answer 4

a) Ta có: $\left(3{}^{}-2x+5\right)-\left({}^{}+4{}^{}-x-7\right)$

$=3{}^{}-2x+5-5{}^{}+x+7$

$=-2{}^{}-x+12$

b) Ta có: $4\left(2x+1\right)-5\left(3x+2\right)$

$=8x+4-15x-10$

=-7x-6