Решите умоляю пожалуйста

▪1.а

$(0.5a - 2b) ^{2} = 0.25 {a}^{2} - 2ab + 4 {b}^{2}$

▪1.б

$(a - \frac{3}{4} b)(\frac{3}{4} b + a) = {a}^{2} - \frac{9}{16} {b}^{2}$

▪2.

$2( {x + 1)}^{2} - (x - 3)(x + 3) = 7 + {x}^{2} \\ 2( {x}^{2} + 2x + 1) - ( {x}^{2} - 9) = 7 + {x}^{2} \\ 2 {x}^{2} + 4x + 2 - {x}^{2} + 9 - 7 - {x}^{2} = 0 \\ 4x + 4 = 0 \\ 4(x + 1) = 0 \: \: \: \: \: | \div 4 \\ x + 1 = 0 \\ x = - 1$

▪3.

$\frac{ {a}^{2} - 10a + 25}{a - 5} = \frac{ {(a - 5)}^{2} }{a - 5} = a - 5 \\ \\ a - 5 = 1.5 - 5 = - 3.5$