Question

a)(X-5)(X+2)+(X+1)(2-X)=15

b)(2X-3)(X+5)-(X-2)(2X+1)=3

Answer 1

a, \(\left(x-5\right)\left(x+2\right)+\left(x+1\right)\left(2-x\right)=15\)

\(\Leftrightarrow x^2+2x-5x-10+2x-x^2+2-x=15\Leftrightarrow-2x-23=0\)

\(\Leftrightarrow x=-\frac{23}{2}\)

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

\(\Leftrightarrow2x^2+10x-3x-15-\left(2x^2+x-4x-2\right)=3\)

\(\Leftrightarrow10x-16=0\Leftrightarrow x=\frac{8}{5}\)

Answer 2

(x -5)(x + 2) + (x + 1)(2 - x) = 15

=> x² - 3x - 10 + x - x² + 2 = 15

=> -2x = 23

=> x = - 11,5

b)(2x - 3)(x + 5) - (x - 2)(2x + 1) = 3

=> 2x² + 7x - 15 - 2x² + 3x + 2 = 3

=> 10x = 16

=> x = 1,6

Vậy x = 1,6

Answer 3

\(a,\left(x-5\right)\left(x+2\right)+\left(x+1\right)\left(2-x\right)=15\)

\(\Leftrightarrow x^2+2x-5x-5x-10+2x-x^2+2-x-15=0\)

\(\Leftrightarrow-7x-23=0\)

\(\Leftrightarrow-7x=23\)

\(\Leftrightarrow x=\frac{-23}{7}\)

Vậy x = \(\frac{-23}{7}\)

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

\(\Leftrightarrow2x^2+10x-3x-15-2x^2-x+4x+2-3=0\)

\(\Leftrightarrow10x-16=0\)

\(\Leftrightarrow x=\frac{16}{10}\)

Vậy x = \(\frac{16}{10}\)

Học tốt nhá :))

Answer 4

a) ( x - 5 )( x + 2 ) + ( x + 1 )( 2 - x ) = 15

<=> x² - 3x - 10 - x² + x + 2 = 15

<=> -2x - 8 = 15

<=> -2x = 23

<=> x = -23/2

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

<=> 2x² + 7x - 15 - ( 2x² - 3x - 2 ) = 3

<=> 2x² + 7x - 15 - 2x² + 3x + 2 = 3

<=> 10x - 13 = 3

<=> 10x = 16

<=> x = 16/10 = 8/5

Answer 5

               Bài làm :

a) (x - 5)(x + 2) + (x + 1)(2 - x) = 15

<=> x² - 3x - 10 + x - x² + 2 = 15

<=> -2x = 23

<=> x = - 11,5

b) (2x - 3)(x + 5) - (x - 2)(2x + 1) = 3

<=> 2x² + 7x - 15 - 2x² + 3x + 2 = 3

<=> 10x = 16

<=> x = 1,6