Question

please answer these questions​

Answer 1

Step-by-step explanation:

8.i) Let the side of a cube be 'a'.

According to the question,

$surface \: area \: of \: cube = 600$

$6 {a}^{2} = 600$

${a}^{2} = \frac{600}{6}$

${a}^{2} = 100$

$a = \sqrt{100}$

$a = 10$

Answer :- The side of a cube is 10 cm.

9.i)

$( {2p + 5)}^{2} - ( {2p - 5)}^{2}$

$= (2p + 5+ 2p - 5)(2p + 5 - 2p + 5) \: \: \: \: ( {a}^{2} - {b}^{2} = (a + b)(a - b))$

$= 4p \times 10$

$= 40p$