Question

please answer atleast 5 question I'll make you branliest and I'll follow you​

Answer 1

Answer:

16.) Ratio of radii of two spheres is 4: 7

$radius \: \: of \: \: 1st \: \: sphere(r1) = 3x \\ radius \: \: of \: \: 2nd \: \: sphere(r2) = 7x \\ ratio \: \: of \: \: volumes \: \: are \: \\ = \frac{v1}{v2} \\ = \frac{ \frac{4}{3}\pi {r1}^{3} }{ \frac{4}{3}\pi {r2}^{3} } \\ = \frac{r {1}^{3} }{r {2}^{3} } \\ = \frac{(3x {)}^{3} }{(7x {)}^{3} } \\ = \frac{27 {x}^{3} }{343 {x}^{3} } \\ = \frac{27}{343}$

ratio of volumes is 27 : 343.

18.)

$circumference \: \: of \: \: base = 120\pi \\ slant \: \: height = 10cm \\ circumference \: \: of \: \: base \: = 2\pi \: r \\ 120\pi = 2\pi \: r \\ 120 = 2r \: \\ \frac{120}{2} = r \: \\ r \: = 60cm \\ csa \: \: of \: \: cone = \pi \: r \: l \\ = \frac{22}{7} \times 60 \times 10 \\ = \frac{13200}{7} \\ = 1885.7c {m}^{2}$

$27.) \frac{ {x}^{2} - 16 }{x + 4} \div \frac{x - 4}{x + 4} \\ = \frac{ {x}^{2} - 16}{x + 4} \times \frac{x + 4}{x - 4} \\ = \frac{ {x}^{2} - 16 }{x - 4} \\ = \frac{ {x}^{2} - {4}^{2} }{x - 4} \\ \: \: \: \: \: \: \: \: using \: \: this \: \: identity \\ {x}^{2} - {y}^{2} = (x + y)(x - y) \\ = \frac{(x - 4)(x + 4)}{(x - 4)} \\ = (x + 4) \: \: ans$

$28.) \frac{p}{q} = a \\ p = qa \\ put \: \: the \: \: value \\ \frac{ {p}^{2} + {q}^{2} }{ {p}^{2} - {q}^{2} } \\ = \frac{(qa {)}^{2} + {q}^{2} }{(qa {)}^{2} - {q}^{2} } \\ using \: \: this \: \: identity \: \: \\ {x}^{2} - {y}^{2} = (x + y)(x - y) \\ = \frac{(qa + q {)}^{2} }{(qa - q)(qa - q)} \\ = \frac{(qa + q)(qa + q)}{(qa - q)(qa + q)} \\ = \frac{(qa + q)}{(qa - q)} \\ = \frac{q(a + 1)}{q(a - 1)} \\ = \frac{(a + 1)}{(a - 1)} ans$

It is very difficult to type all the questions so , I have solved only 4 small questions and next time give more points of this long questions.

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I hope it will help you