Question

please find answers ​

Answer 1

hey mate,...here's your answer,...

1)

$4 {x}^{2} - 25 {y}^{2} \\ = {a}^{2} - {b}^{2} = (a + b)(a - b) \\ (2x + 5y)(2x - 5y)$

and

${y}^{2} - 4 \\ = {y}^{2} - {2}^{2} \\ (a + b)(a - b) \\ (y + 2)(y - 2)$

2) area of rectangle is l×b

I.e.,

$40 \times 45 = 1800 {m}^{2}$

3)

$16 \: cycles = = = 17600 \\ 9 \: cycles = = = = \: x \\ x = \frac{1760 \times 9}{16} \\ x = 660$

am sorry but am not known with the last one,..

hope it helps you,..and

pls mark me as the brainliest,...