Go through the Math in Focus Grade 5 Workbook Answer Key Chapter 5 Algebra to finish your assignments.

Math Journal

John’s solutions to the following problems are as shown. Identify and explain the mistakes John has made. Then give the correct solution.

Question 1.
4w + 12w – 10 = 16w – 10
= 6 w
4w + 12w – 10 = 16w – 10
Explanation:
John has made a mistake in subtracting number from a variable type of number. So, the correct solution is 16w – 10.

Question 2.
20p – 2p + 4p = 20p – 6 p
= 14p
20p – 2p + 4p = 24p – 2p = 22p
Explanation:
John has made a mistake in the order of subtraction and additions. First we should add all the numbers and then subtract the numbers. So, the correct solution is 22p.

Question 3.
6 ÷ q = $$\frac{q}{6}$$
6 ÷ q = 6/q
Explanation:
John has made a mistake in putting the numerator and denominator of a division.
The number before the division symbol (÷) should be consider as numerator.
The number after the division symbol (÷) should be consider as denominator.
So, the correct solution is 6/q.

Question 4.
Clarissa bought 3 cartons of milk for y cents each. She gave the cashier $10. How much change did she receive? Express your answer in terms of y. Answer: 3 × y = 3y 3 cartons of milk cost 3y cents.$1 = 100 cents
So, $10 = 1,000 cents Hence, Clarissa received (1,000 – 3y) cents in change. Put On Your Thinking Cap! Challenging Practice Wendy bought 7 handbags. Each handbag costs the same amount. She paid the cashier$100 and received g dollars in change.

a. What was the cost of each handbag in terms of g?
Total money paid to cashier is $100. Total number of handbags bought = 7 Total change received = g$
So, cost of 7 handbags = (100-g)$Cost of each handbag = (100-g)/7$

b. If the price of each handbag was more than $1 0, what is the least possible value of g? (Assume that the cost of each handbag is a whole number.) Answer: Assume that each handbag costs 10$, then change given is (100-(7×10)) =(100-70)$= 30$
Assume that each handbag costs 12$, then change given is (100-(7×12)) =(100-84)$ = 16$Assume that each handbag costs 14$, then change given is (100-(7×14)) =(100-98)$= 2$
So, the least possible value of g is 2.

Problem Solving

There are 40 pupils in a class. There are x more girls than boys.

a. How many boys are there in terms of x?