Question

evaluate the expression below when x = 3. 5x2 - 12x + 3

Answer 1

The possible answers are

1.) 3
2.) 11/3
3.) 11/2
4.) 26/3

Answer 2

\(5x^2 - 12x + 3\)

Input 3 for x:

\(5(3)^2 - 12(3) + 3\)

The exponent is over the 3, so we have to simplify \(3^2\).

\(5(9) - 12(3) + 3\)

5 * 9 = 45

\(45 - 12(3) + 3\)

-12 * 3 = -36

\(45 - 36 + 3\)

45 - 36 = 9

\(9 + 3\)

9 + 3 = 12

\(12\)

Answer 3

I did something wrong.

Answer 4

But it seems correct..

Answer 5

That's correct.. the answer is 12.. right, @mathmale ?

Answer 6

@JulianoRossiel

Answer 7

No the following are

1.) 3
2.) 11/3
3.) 11/2
4.) 26/3

Answer 8

Are you sure this is the expression? @JulianoRossiel

\(5x^2 - 12x + 3\)

Answer 9

I like the approach 'iGreen' has taken here: He/she has replaced every occurrence of 'x' with parentheses enclosing the x value: x => (3).
Note how your 'x2' (which should be written 'x^2' becomes (3)^2, or 9.

Answer 10

'x squared' can be written as x^2, \[x^2\] or

Answer 11

I have made no mathematical errors..

Answer 12

but preferably not 'x2'.

Answer 13

Yet my answer is not one of the options.

Answer 14

evaluate the expression below when x = 3. 5x2 - 12x + 3:

or, evaluate 5x^2 - 12x + 3 for x = 3:

5(3)^2 - 12(3) + 3 = 5(9) -36 + 3 = ???

Answer 15

5(9) - 36 + 3

5 * 9 = 45

45 - 36 + 3

9 + 3

12

Answer 16

However, 12 is not an option.

12 ≠ 3
12 ≠ 11/3
12 ≠ 11/2
12 ≠ 26/3

Answer 17

5x^2-12/x+3

Sorry I wrote the equation wrong

Answer 18

Uh-oh.

Please replace each occurrence of 'x' with '(x)' now. Then evaluate the expression.

Answer 19

I need help the expression

Answer 20

\(\dfrac{5x^2-12}{x+3}\)

Input 3 in for every \(x\) term:

\(\dfrac{5(3)^2-12}{(3)+3}\)

Simplify the exponent:

\(\dfrac{5(9)-12}{3+3}\)

Multiply:

\(\dfrac{45-12}{3+3}\)

Subtract:

\(\dfrac{33}{3+3}\)

Add:

\(\dfrac{33}{6}\)

Simplify the fraction:

\(\dfrac{11}{2}\)

Answer 21

Welcome to Open Study!

You can give medals by clicking 'Best Response'. @JulianoRossiel

Answer 22

I will and thanks for your help