Question

(2x+3)² - (2x+1).(2x-1)=22

Mọi người giúp mình với :<

Answer 1

\(\left(2x+3\right)^2-\left(2x+1\right)\left(2x-1\right)=22\)

\(\left(4x^2+12x+9\right)-\left(4x^2-1^2\right)=22\)

\(4x^2+12x+9-4x^2+1=22\)

\(12x+10=22\)

\(12x=12\)

\(x=1\)

Answer 2

(2x+3)² - (2x+1).(2x-1)=22

\(4x^2+12x+9-4x^2-1=22\)

\(12x+8 =22\)

\(12x=14\)

\(x=7/6\)

Answer 3

(2x + 3)² - (2x + 1)(2x - 1) = 22

<=> 4x² + 12x + 9 - 4x² + 1 = 22

<=> 4x² - 4x² + 12x = 22 - 9 - 1

<=> 12x = 12

<=> x = 1

Answer 4

\(\left(2x+3\right)^2-\left(2x+1\right)\left(2x-1\right)=22\)

\(\Leftrightarrow4x^2+12x+9-4x^2+1=22\)

\(\Leftrightarrow12x=12\)

hay x=1