Question

masteryprep for the act math student workbook
8.1 entrance ticket
solve the questions below.

1. if ( x = -2 ), then ( x + 4 = )?

a. -6
b. -2
c. 2
d. 6

1. when ( x = 3 ), what is the value of ( x^2 - 4 )?

f. -1
g. 2
h. 5
j. 13

1. what is the value of the expression ( 2x^2 + x ), if ( x ) is 3?

a. 9
b. 18
c. 21
d. 27

Explanation:

Question 1

Step1: Substitute \( x = -2 \) into \( x + 4 \)

\( x + 4 = -2 + 4 \)

Step2: Calculate the result

\( -2 + 4 = 2 \)

Step1: Substitute \( x = 3 \) into \( x^2 - 4 \)

\( x^2 - 4 = 3^2 - 4 \)

Step2: Calculate \( 3^2 \)

\( 3^2 = 9 \)

Step3: Subtract 4 from the result

\( 9 - 4 = 5 \)

Step1: Substitute \( x = 3 \) into \( 2x^2 + x \)

\( 2(3)^2 + 3 \)

Step2: Calculate \( 3^2 \)

\( 3^2 = 9 \)

Step3: Multiply by 2

\( 2\times9 = 18 \)

Step4: Add 3 to the result

\( 18 + 3 = 21 \)

Answer:

C. 2

Question 2