What is the value of the expression 3b - a 2 when a = 3 and b = 4?

Question

asked Sep 19, 2024 69.1k views

2 Answers

Rico Neitzel · Answer 1 · 2024-09-21T11:26:03+0000

Answer: 3

Explanation:

Our task is to find the value of
$\sf{3b-a^2}$ when a = 3 and b = 4.

Replace each variable with its value. You should get this:

$\sf{3\cdot4-3^2}$

This is where many students can make mistakes. We need to follow the order of operations listed in PEMDAS:

Parentheses, exponents, multiplication, division, addition, and subtraction

We don't have parentheses here, so we move on to exponents, which we do have. We have 3 squared, which is 9.

So, we now have:

$\sf{3\cdot4-9}$

The operation that comes next is multiplication. We multiply 3 by 4, which gives us 12.

$\sf{12-9}$

We now have to subtract to get our final answer:

$\sf{12-9=3}$

The expression's value is 3.