Question

The value of 4x^2-5 when x=3

Answer 1

31

Explanation:

substitute 3 for x in 4x^2-5: 4(3)^2 - 5 = 4(9) - 5 = 36 - 5 = 31

Answer 2

31

Explanation:

Plug in 3 for x in the expression:

4(3²) - 5

Note that there are no parenthesis (other than the one I added, to make it easier for you. Follow the order of operations, PEMDAS. PEMDAS = Parenthesis, Exponents (& Roots), Multiplication, Division, Addition, Subtraction, and the left -> right rule.

First, solve the exponent:

4(3²) - 5 = 4(3 * 3) - 5 = 4(9) - 5

Next, solve the multiplication:

4(9) - 5 = 36 - 5

Finally, subtract:

36 - 5 = 31

31 is your answer.

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