Examples for √a+√b is not equal to √a+b​

Carley bought a jacket that was discounted 10% off the original price. the expression below represents the discounted price in dollars, based on x, the original price of the jacket.

Given a normal distribution with µ=20 and σ = 4, what is the probability that x> 24 x< 24 x< 24 or x> 24

Similarly fie each expression 18,19,20