4x^2-25= (2x)^2-5^2=(2x-5)(2x+5)
Used: a^2-b^2=(a+b)(a-b)
Answer:
Rohit takes 4 4/5 minutes ( =4.8 minutes) to make a complete round of a circular park. For finishing 15 rounds, he needs time T:
T = 15 x 4.8 = 72 minutes
Hope this helps!
:)
SOH CAH TOA tells you
Cos(x) = Adjacent/Hypotenuse
so you can find
x = arccos(24/28)
x ≈ 31.0°
