Question

помогите срочно 40 баллов

Answer 1

$Задание \: \: №1$

$1. \: \: \: \: \: {4k}^{4} {t}^{2} - {kt}^{2} - {(2 {k}^{2}t) }^{2} = {4k}^{4} {t}^{2} - {kt}^{2} - {4k}^{4} {t}^{2} = - {kt}^{2}$

$2. \: \: \: \: \: 3xy \times 5y - 2y \times 7x - 4 {xy}^{2} = 15 {xy}^{2} - 14xy - {4xy}^{2} = 11 {xy}^{2} - 14xy$

$3. \: \: \: \: \: 5 {m}^{2} n + \frac{6}{7} n - 3 {nm}^{2} + 5nmm + 3.2m = 5 {nm}^{2} + \frac{6}{7} n - {3nm}^{2} + 5 {nm}^{2} + 3.2m = 7 {nm}^{2} + \frac{6}{7} n + 3.2m$

$4. \: \: \: \: \: 4 {x}^{3} \times ( - {3y}^{2} ) - 2 {xy}^{2} \times 3x + {5x}^{2} {y}^{2} \times 2y = - 12 {x}^{3} {y}^{2} - 6 {x}^{2} {y}^{2} + 10 {x}^{2} {y}^{3}$

$Задание \: \: №2$

${4mn}^{2} - 0.5 \times 4n + 15mn - 12 {nm}^{2} = 4 {mn}^{2} - 2n + 15mn - 12 {nm}^{2}$

$m = - 2 \: \: ; \: \: n = 5$

${4mn}^{2} - 2n + 15mn - 12n {m}^{2} = 4 \times ( - 2) \times {5}^{2} - 2 \times 5 + 15 \times ( - 2) \times 5 - 12 \times 5 \times {( - 2)}^{2} = - 200 - 10 - 150 - 240 = - 600$