Practice the problems of Math in Focus Grade 8 Workbook Answer Key Chapter 6 Functions to score better marks in the exam.

## Math in Focus Grade 8 Course 3 A Chapter 6 Answer Key Functions

### Math in Focus Grade 8 Chapter 6 Quick Check Answer Key

**Write an algebraic expression for each of the following.**

Question 1.

Benedict has 7 packs of cards. Each pack has x cards. He gives 3 cards to his sister. Write an algebraic expression for the number of cards that he has left.

Answer:

Given,

Benedict has 7 packs of cards.

Each pack has x cards.

He gives 3 cards to his sister.

7x – 3

Thus the algebraic expression for the number of cards that he has left is 7x – 3.

Question 2.

y highlighters are shared equally among 9 students. One of the students, Jessie, then buys another 3 highlighters. Write an algebraic expression for the number of highlighters she has in total.

Answer:

Given,

y highlighters are shared equally among 9 students.

One of the students, Jessie, then buys another 3 highlighters.

y/9 + 3

**Evaluate each expression for the given value of the variable.**

Question 3.

5x + 7 when x = -3

Answer:

Given the expression 5x + 7

when x = -3

5(-3) + 7

= -15 + 7

= -8

Question 4.

-4x – 1 when x = 3

Answer:

Given the expression -4x – 1

when x = 3

-4(3) – 1

-12 – 1 = -13

Question 5.

3 – \(\frac{1}{2}\)x when x = -5

Answer:

Given the expression 3 – \(\frac{1}{2}\)x

when x = -5

3 – \(\frac{1}{2}\)(-5)

3 + \(\frac{5}{2}\)

Question 6.

\(\frac{3}{4}\)x – 2 when x = 7

Answer:

Given the expression \(\frac{3}{4}\)x – 2

when x = 7

\(\frac{3}{4}\)(7) – 2

\(\frac{21}{4}\) – 2