Question

Решите уравнение
(3х+1)²-9(х+1)(х-1)=0
1/9х²=0,81

Answer 1

${(3x + 1)}^{2} - 9(x + 1)(x - 1) = 0 \\ \\ 9 {x}^{2} + 6x + 1 - 9( {x}^{2} - 1) =0 \\ \\ = 9 {x }^{2} + 6x + 1 - 9 {x}^{2} + 9 = 0 \\ \\ 6x + 10 = 0 \\ \\ 6x = - 10 \\ \\ x = - \frac{5}{3} = - 1 \frac{2}{3}$

$\frac{1}{9} {x}^{2} = 0.81 \\ \\ {x}^{2} = 7.29 \\ \\ x1 = 2.7 \\ \\ x2 = - 2.7$

Answer 2

9x^2 + 6x + 1-9(x^2 -1)=0
9x^2 + 6x + 1- 9x^2+9 =0
6x+10=0
x= -5/3

19/10 x^2 = 81/ 100
x^2 =81/190
x = плюс минус 9 корень 190 поделить 190