Question

a) (2x+3)(x-4)+(x-5)(x-2)=(3x-5)(x-4)

b)(8x-3)(3x+2)-(4x+7)(x+4)=(2x+1)(5x-1)

c)(\(^{x^2}\)-5)(x+2)+5x=2\(^{x^2}\)+17

d)(\(^{x^2}\)-x+1)(x+1)-\(x^3\)+3x=15

Answer 1

a: \(\Leftrightarrow2x^2-8x+3x-12+x^2-7x+10=3x^2-12x-5x+20\)

\(\Leftrightarrow3x^2-12x-2=3x^2-17x+20\)

=>5x=22

hay x=22/5

b: \(\Leftrightarrow24x^2+16x-9x-6-4x^2-16x-7x-28=10x^2-2x+5x-1\)

\(\Leftrightarrow20x^2-16x-34=10x^2+3x-1\)

\(\Leftrightarrow10x^2-19x-33=0\)

hay \(x\in\left\{3;-\dfrac{11}{10}\right\}\)

c: \(\Leftrightarrow x^3+2x^2-5x-10+5x=2x^2+17\)

\(\Leftrightarrow x^3+2x^2-10-2x^2-17=0\)

=>x³=27

=>x=3

d: \(\Leftrightarrow x^3+1-x^3+3x=15\)

=>3x=14

hay x=14/3