Question 1

LEVEL 6

If f(x) = x -9, find f(6).

Select the correct answer from the list below:

A: -3

B: 6

C: 3

D: -6

 

CORRECT ANSWER:    A: -3

WORKED SOLUTION:

Substitute x=6 into the equation.

f(6) = 6 -9 = -3

Question 2

LEVEL 6

If f(x) = \dfrac{x}{6}, find f(36)

Select the correct answer from the list below:

A: 3

B: 9

C: 6

D: 1

 

CORRECT ANSWER:   C: 6

WORKED SOLUTION:

Substitue x=6 into the equation.

f(36) = \dfrac{36}{6}=6

Question 3

LEVEL 6

If f(x) = -5(2x+1)^2, find f(3)

Select the correct answer from the list below:

A:-165

B: -75

C: -35

D: -245

 

CORRECT ANSWER:   D: -245

 

WORKED SOLUTION:

Substitue x=3 into the equation.

f(3) = -5(2(3)+1)^2 = -5(7)^2 = -5 \times 49=-245

Question 4

LEVEL 6

If f(x) = \dfrac{2x+1}{4}, find f(3.5)

Select the correct answer from the list below:

A: 1

B: 4

C: 2

D: 3

 

CORRECT ANSWER:     C: 2

WORKED SOLUTION:

Substitue x=3.5 into the equation.

f(3.5) = \dfrac{2(3.5)+1}{4} = \dfrac{7+1}{4} = 2

Question 5

LEVEL 6

f(x) = 2x+1

Solve f(x) = 3 to find x.

Select the correct answer from the list below:

A: x = 7

B: x = 1

C: x = 2

D: x = 4

 

CORRECT ANSWER:       B: x = 1

WORKED SOLUTION:

Rearrange the formula to find x

f(x) = 2x+1 = 3

2x= 3-1

x= 1

Question 6

LEVEL 6

f(x) = \dfrac{2x}{3}

Solve f(x) = 30 to find x.

Select the correct answer from the list below:

A: x = 45

B: x = 60

C: x = 40

D: x = 90

 

CORRECT ANSWER:    A: x = 45

WORKED SOLUTION:

Rearrange the formula to find x

f(x) = \dfrac{2x}{3} = 30

2x = 90

x= 45