Go through the Math in Focus Grade 7 Workbook Answer Key Chapter 3 Lesson 3.2 Subtracting Algebraic Terms to finish your assignments.
Math in Focus Grade 7 Course 2 A Chapter 3 Lesson 3.2 Answer Key Subtracting Algebraic Terms
Math in Focus Grade 7 Chapter 3 Lesson 3.2 Guided Practice Answer Key
Copy and complete to simplify each expression.
Question 1.
0.7y – 0.4y
0.7y – 0.4y =
Answer:
Explanation:
0.7y – 0.4y
= 0.3y.
Question 2.
1.1a – 0.2a
1.1a – 0.2a =
Answer:
Explanation:
1.1a – 0.2a
=0.9a
Question 3.
1.2y – y
1.2y – y =
Answer:
1.2y – y = 0.2y.
Explanation:
1.2y – y
= 0.2y.
Copy and complete to simplify each expression.
Question 4.
\(\frac{4}{9}\)x – \(\frac{1}{3}\)x
The LCD of \(\frac{4}{9}\) and \(\frac{1}{3}\) is .
So, x is divided into x sections.
\(\frac{4}{9}\)x – \(\frac{1}{3}\)x =
Answer:
\(\frac{4}{9}\)x – \(\frac{1}{3}\)x = \(\frac{1}{9}\)x.
Explanation:
The LCD of \(\frac{4}{9}\) and \(\frac{1}{3}\) is 9.
So, x is divided into 9 x sections.
\(\frac{4}{9}\)x – \(\frac{1}{3}\)x
= [4 – (1 × 3)]x ÷ 9
= (4 – 3)x ÷ 9
= x ÷ 9 or \(\frac{1}{9}\)x
Question 5.
\(\frac{3}{4}\)p – \(\frac{1}{6}\)p
\(\frac{3}{4}\)p – \(\frac{1}{6}\)p =
=
Rewrite the coefficients as fractions with denominator .
Answer:
\(\frac{3}{4}\)p – \(\frac{1}{6}\)p = \(\frac{7}{12}\)p.
Explanation:
\(\frac{3}{4}\)p – \(\frac{1}{6}\)p
LCD of 4 n 6 = 12.
= [(3 × 3) – (1 × 2)]p ÷ 12
= (9 – 2)p ÷ 12
= 7p ÷ 12 or \(\frac{7}{12}\)p
Math in Focus Course 2A Practice 3.2 Answer Key
Simplify each expression with decimal coefficients.
Question 1.
0.8y – 0.7y
Answer:
0.8y – 0.7y = 0.1y.
Explanation:
0.8y – 0.7y = 0.1y.
Question 2.
0.9x – 0.6x
Answer:
0.9x – 0.6x = 0.3x.
Explanation:
0.9x – 0.6x = 0.3x.
Question 3.
1.7p – 0.4p
Answer:
1.7p – 0.4p = 1.3p.
Explanation:
1.7p – 0.4p = 1.3p.
Question 4.
1.9h – 0.9h
Answer:
1.9h – 0.9h = 1.0h.
Explanation:
1.9h – 0.9h = 1.0h.
Question 5.
1.3m – 0.5m
Answer:
1.3m – 0.5m = 0.8m.
Explanation:
1.3m – 0.5m = 0.8m.
Question 6.
1.6n – 0.8n
Answer:
1.6n – 0.8n = 0.8n.
Explanation:
1.6n – 0.8n = 0.8n.
Simplify each expression with fractional coefficients.
Question 7.
\(\frac{5}{6}\)x – \(\frac{1}{6}\)x
Answer:
\(\frac{5}{6}\)x – \(\frac{1}{6}\)x = \(\frac{2}{3}\)x
Explanation:
\(\frac{5}{6}\)x – \(\frac{1}{6}\)x
= (5 – 1)x ÷ 6
= 4x ÷ 6
= 2x ÷ 3 or \(\frac{2}{3}\)x
Question 8.
\(\frac{7}{8}\)x – \(\frac{5}{8}\)x
Answer:
\(\frac{7}{8}\)x – \(\frac{5}{8}\)x = \(\frac{1}{4}\)x.
Explanation:
\(\frac{7}{8}\)x – \(\frac{5}{8}\)x
= (7 – 5)x ÷ 8
= 2x ÷ 8
= x ÷ 4 or \(\frac{1}{4}\)x
Question 9.
\(\frac{9}{5}\)x – \(\frac{1}{5}\)x
Answer:
\(\frac{9}{5}\)x – \(\frac{1}{5}\)x = \(\frac{8}{5}\)x.
Explanation:
\(\frac{9}{5}\)x – \(\frac{1}{5}\)x
= (9 – 1)x ÷ 5
= 8x ÷ 5 or \(\frac{8}{5}\)x.
Question 10.
\(\frac{8}{3}\)p – \(\frac{1}{3}\)p
Answer:
\(\frac{8}{3}\)p – \(\frac{1}{3}\)p = \(\frac{7}{3}\)p.
Explanation:
\(\frac{8}{3}\)p – \(\frac{1}{3}\)p
= (8 – 1)p ÷ 3
= 7p ÷ 3 or \(\frac{7}{3}\)p.
Simplify each expression with fractional coefficients by rewriting the fractions.
Question 11.
\(\frac{1}{4}\)a – \(\frac{1}{8}\)a
Answer:
\(\frac{1}{4}\)a – \(\frac{1}{8}\)a = \(\frac{1}{8}\)a.
Explanation:
\(\frac{1}{4}\)a – \(\frac{1}{8}\)a
= LCD of 4 n 8 = 8.
= (2 – 1)a ÷ 8
= a ÷ 8 or \(\frac{1}{8}\)a
Question 12.
\(\frac{5}{6}\)m – \(\frac{2}{3}\)m
Answer:
\(\frac{5}{6}\)m – \(\frac{2}{3}\)m = \(\frac{1}{6}\)m
Explanation:
\(\frac{5}{6}\)m – \(\frac{2}{3}\)m
= LCD of 6 n 3 = 6.
= [5 – (2 × 2)]m ÷ 6
= (5 – 4)m ÷ 6
= m ÷ 6 or \(\frac{1}{6}\)m
Question 13.
\(\frac{5}{3}\)b – \(\frac{1}{6}\)b
Answer:
\(\frac{5}{3}\)b – \(\frac{1}{6}\)b = \(\frac{1}{2}\)b.
Explanation:
\(\frac{5}{3}\)b – \(\frac{1}{6}\)b
= LCD of 3 n 6 = 6.
= [(5× 2) – 1]b ÷ 6
= (10 – 1)b ÷ 6
= 9b ÷ 6
= 3b ÷ 6
= b ÷ 2 or \(\frac{1}{2}\)b.
Question 14.
\(\frac{7}{4}\)x – \(\frac{1}{8}\)x
Answer:
\(\frac{7}{4}\)x – \(\frac{1}{8}\)x = \(\frac{13}{8}\)x.
Explanation:
\(\frac{7}{4}\)x – \(\frac{1}{8}\)x
LCD of 4 n 8 = 8.
= [(7 × 2) – 1]x ÷ 8
= (14 – 1)x ÷ 8
= 13x ÷ 8 or \(\frac{13}{8}\)x.
Question 15.
\(\frac{4}{5}\)p – \(\frac{1}{3}\)p
Answer:
\(\frac{4}{5}\)p – \(\frac{1}{3}\)p = \(\frac{2}{3}\)p.
Explanation:
\(\frac{4}{5}\)p – \(\frac{1}{3}\)p
LCD of 5 n 3 = 15.
= [(4 × 3) – (1 × 5)]p ÷ 15
= (15 – 5)p ÷ 15
= 10p ÷ 15
= 2p ÷ 3 or \(\frac{2}{3}\)p.
Question 16.
\(\frac{3}{4}\)r – \(\frac{2}{3}\)r
Answer:
\(\frac{3}{4}\)r – \(\frac{2}{3}\)r = \(\frac{1}{12}\)r.
Explanation:
\(\frac{3}{4}\)r – \(\frac{2}{3}\)r
LCD of 4 n 3 = 12.
= [(3 × 3) – (2 × 4)]r ÷ 12
= (9 – 8)r ÷ 12
= r ÷ 12 or \(\frac{1}{12}\)r.
Question 17.
\(\frac{11}{7}\)k – \(\frac{1}{2}\)k
Answer:
\(\frac{11}{7}\)k – \(\frac{1}{2}\)k = \(\frac{15}{14}\)k.
Explanation:
\(\frac{11}{7}\)k – \(\frac{1}{2}\)k
LCD of 7 n 2 = 14.
= [(11 × 2) – (1 × 7)]k ÷ 14
= (22 – 7)k ÷ 14
= 15k ÷ 14 or \(\frac{15}{14}\)k.
Question 18.
\(\frac{7}{4}\)d – \(\frac{3}{5}\)d
Answer:
\(\frac{7}{4}\)d – \(\frac{3}{5}\)d = \(\frac{23}{20}\)d.
Explanation:
\(\frac{7}{4}\)d – \(\frac{3}{5}\)d
LCD of 4 n 5 = 20.
= [(7 × 5) – (3 × 4)]d ÷ 20
= (35 – 12)d ÷ 20
= 23d ÷ 20 or \(\frac{23}{20}\)d.
Solve. Show your work.
Question 19.
Math Journal Matthew simplified the algebraic expression \(\frac{3}{2}\)x – \(\frac{1}{3}\)x as shown below.
\(\frac{3}{2}\)x – \(\frac{1}{4}\)x = \(\frac{18}{12}\)x – \(\frac{4}{12}\)x
= \(\frac{14}{12}\)x
Is Matthew’s simplification correct? Why or why not?
Answer:
Matthew’s simplification is incorrect because \(\frac{3}{2}\)x – \(\frac{1}{4}\)x is not equal to \(\frac{18}{12}\)x – \(\frac{4}{12}\)x.
Explanation:
\(\frac{3}{2}\)x – \(\frac{1}{4}\)x
LCD of 2 n 4 = 4.
= [(3 × 2) – (1 × 1)]x ÷ 4
= (6 – 1)x ÷ 4
= 5x ÷ 4 or \(\frac{5}{4}\)x.
\(\frac{18}{12}\)x – \(\frac{4}{12}\)x
= (18 – 4)x ÷ 12
= 14x ÷ 12
= 7x ÷ 6 or \(\frac{7}{6}\)x.
\(\frac{14}{12}\)x = \(\frac{7}{6}\)x
Question 20.
Rectangle A, shown below, is larger than rectangle B. Write and simplify an algebraic expression that represents the difference in the areas of the two rectangles.
Answer:
Difference in the Area of rectangle A and Area of rectangle B = 11.7 square cm.
Explanation:
Area of rectangle A = Length × Width
= 4.5cm × 3cm
= 13.5 square cm.
Area of rectangle B = Length × Width
= 0.9cm × 2cm
= 1.8 square cm.
Difference in the Area of rectangle A and Area of rectangle B:
= 13.5 square cm – 1.8 square cm
= 11.7 square cm.