Question

пж рещите 2 вариант...​ даю 100б

Answer 1

Пошаговое объяснение:

$(2 \times \frac{3}{4} - 1.5) + (2.5 - 1 \times \frac{7}{8} ) \div \frac{1}{8} - 0.25 = 1 \times \frac{1}{4} + \frac{5}{8} \times 8 - 0.25 = 1 \times \frac{1}{4} + 5 - 0.25 = 6$

${x}^{25} \div {( {x}^{7} )}^{3} = {x}^{25} \div {x}^{7 \times 3} = {x}^{25} \div {x}^{21} = {x}^{25 - 21} = {x}^{4}$

$7(3 - x) - 4(2x - 1) = 21 - 7x - 6x + 4 = - 13x + 25$

$\frac{7 \times \frac{1}{3} }{2 \times \frac{1}{2} } = \frac{3 \times \frac{2}{3} }{y} \\ y = \frac{2 \times \frac{1}{2} \times 3 \times \frac{2}{3} }{7 \times \frac{1}{3} } = \\ = \frac{5}{7 \times \frac{1}{3} } = \frac{5}{21}$

$3x - 2y = 16 \\ x + 4y = - 4$

$6x - 4y = 32 \\ x + 4y = - 4$

$7x = 28 \\ x + 4y = - 4$

$x = 4 \\ 4y = - 4 - x$

$x = 4 \\ 4y = - 4 - 4 = - 8$

$x = 4 \\ y = -2$