Question

please answer with full explanation​

Answer 1

Answer:

PLEASE PREFER TO THE ATTACHMENT

Answer 2

Answer:

$10)Let \: their \: presents \: age \: be \: x . \\ </p><p>According \: to \: the \: question, \\ \frac{8x + 5}{9x + 5} = \frac{9}{10} \\ Cross \: multiply \\ 10(8x + 5) = 9(9x + 5) \\ 80x + 50 = 81x + 45 \\ 80x - 81x = 45 - 50 \\ ( - x) = ( - 5) \\ x = 5 \\ 8x + 5 = 8(5) + 5 = 40 + 4 = 45 \\ 9x + 5= 9(5) + 5 = 45 + 5 = 50 \\ Therefor, \: their \: present \: ages \: are \: 45 \: and \: 50 \: years.$

$11) a){x}^{2} - 5x + 4 \\ = {x}^{2} - x - 4x + 4 \\ = ( {x}^{2} - x) - (4x + 4) \\ = x(x - 1) - 4(x - 1) \\ = (x - 1)(x - 4) \\ \\ b) {y}^{2} + 2y - 15 \\ = {y}^{2} + 5y - 3y- 15 \\ = ( {y}^{2} + 5y) - (3y - 15) \\ =y(y + 5) - 3(y + 5) \\ = (y + 5)(y - 3)$

$12)Volume of cylinder=88 cm³ \\ </p><p>πr²h=88 \\ </p><p> \frac{22}{7} ×r²×63=88 \\ </p><p>r²=88× \frac{1}{63} × \frac{7}{22} \\ </p><p>r²= \frac{4}{9} \\ </p><p>r= \sqrt{ \frac{4}{9} } \\ </p><p>r= \frac{2}{3} \\ </p><p>r=1.5cm \\ </p><p>C.S.A of cylinder \\ </p><p>=2\pi \: rh = 2 \times \frac{22}{7} \times 1.5 \times 63 \\ = 2 \times 22 \times 1.5 \times 9 \\ = 594 {cm}^{2} \\ </p><p>T.S.A. of cylinder \\ </p><p>=2\pi \: r(h + r) \\ = 2 \times \frac{22}{7} (63 + 1.5) \\ = 2 \times \frac{22}{7 } \times 64.5 \\ = \frac{2838}{7} \\ = 405.43 {cm}^{2}$