CPM Homework Help : CC3 Problem 7-42

CPM Homework Banner

Home > CC3 > Chapter 7 > Lesson 7.2.1 > Problem 7-42

7-42.

Simplify the following expressions.

$- \frac { 3 } { 4 } - \frac { 2 } { 5 }$
Step 1 (a):
Change to addition.
Step 2 (a):
Find a common denominator.
Answer (a):
$-\frac{23}{20}$

$\frac { 7 } { 8 } - \frac { 2 } { 3 }$
Hint (b):
Find a common denominator.

$\frac { 1 } { 3 } - \frac { 5 } { 6 }$
Hint (c):
Refer to part (a).

$1 \frac { 2 } { 3 } + ( - \frac { 2 } { 5 } )$
Hint (d):
Recall that adding a negative number is essentially subtraction.

$\frac { 4 } { 7 } - ( - \frac { 3 } { 8 } )$
Hint (e):
Remember that when you subtract a negative number you are essentially adding it.
Answer (e):
$\frac{53}{56}$

$- 4 \frac { 1 } { 2 } + 3 \frac { 1 } { 9 }$
Hint (f):
Remember, the solution will have the same sign as the larger number.
Answer (f):
$-1\frac{7}{18}$

© 2022 CPM Educational Program. All rights reserved.