Question

Tìm x:
a.(5+x)(x-5)-x(x+5)=10
b.x(2x+3)-2(x²+x)=2

Answer 1

a) (5 + x)(x - 5) - x(x + 5) = 10

x² - 25 - x² - 5x = 10

-5x = 10 + 25

-5x = 35

x = 35 : (-5)

x = -7

b) x.(2x + 3) - 2(x² + x) = 2

2x² + 3x - 2x² - 2x = 2

x = 2

Answer 2

a: \(\left(x+5\right)\left(x-5\right)-x\left(x+5\right)=10\)

=>\(x^2-25-x^2-5x=10\)

=>-5x-25=10

=>-5x=35

=>x=-7

b: \(x\left(2x+3\right)-2\left(x^2+x\right)=2\)

=>\(2x^2+3x-2x^2-2x=2\)

=>x=2