Question

помогите пожалуйста решить

Answer 1

1.

$4 {x}^{4} \times { ( - 3 {x}^{2} ) }^{3} = 4 {x}^{4} \times ( - 27 {x}^{6} ) = - 108 {x}^{10} \\ 3(x - 7) - 5(9 + 2x) = 3x - 21 - 45 - 10x = - 7x - 66 \\ (3x - 1)(3x + 1) + {(x + 1)}^{2} = 9 {x}^{2} - 1 + {x}^{2} + 2x + 1 = 10 {x}^{2} + 2x$

2.

$10 {x}^{2} - 5x = 5x(x - 1) \\ 25x - x {y}^{2} = x(25 - {y}^{2} ) = x(5 - y)(5 + y) \\ 3 {x}^{2} - 6x + 3 = 3( {x}^{2} - 2x + 1) = 3 {(x - 1)}^{2}$

$7x - 5 = 2(x + 9) \\ 7x - 5 = 2x + 18 \\ 7x - 2x = 18 + 5 \\ 5x = 23 \\ x = 23 \div 5 \\ x = 4.6$

$\frac{x - 4}{2} + 3x = 5 \\ x - 4 + 6x = 10 \\ 7x = 14 \\ x = 2$