Answer:
13
Step-by-step explanation:
a = 3
b = -2
a² + b² = 3² + (-2)²
= 9 + 4
= 13
Before we get started, it is good to remember PEMDAS - the acronym that tells you the order to carry out equations.
P = parentheses
E = exponents
M = multiplication
D = division
A = addition
S = subtraction
Knowing this, we should start by doing the equations <em>within </em>each parentheses.

So we did the addition and subtraction pieces within each group leaving us with the above equation. Now let's multiply:

20 is the answer.
If we know that 30% of the time is used after 9 minutes we can write this mathematically as:

By solving for x we can determine the total time allowed to play games and so:

The total time allowed to play games is 30 minutes. Since 9 minutes have lapsed 30-9=21 minutes left to play.
Well the first equation has a variable in it while the other one doesn't also the first expression if set equal to 0 is -2 while the other one is 5