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Q60.

Expert-verified
Found in: Page 7

### Pre-algebra

Book edition Common Core Edition
Author(s) Ron Larson, Laurie Boswell, Timothy D. Kanold, Lee Stiff
Pages 183 pages
ISBN 9780547587776

# Find the sum or difference. (p. 749)$9.9-5.4$

The value of the expression is $4.5$.

See the step by step solution

## Step-1 – Apply the concept of addition and subtraction

Two numbers with similar signs get added and the resulting number carries the similar sign.

Two numbers with opposite signs get subtracted and the resulting number carries the sign of the larger number.

## Step-2 – Apply the concept for addition and subtraction of decimals

To add or subtract two decimal numbers, write the numbers vertical with decimal point aligned vertically.

For example: to add the numbers 2.3 and 4.62, write these numbers vertically and add as shown below

$\begin{array}{l}\text{\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}}2.3\\ \underset{¯}{+4.62}\\ \text{\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}}6.92\end{array}$

## Step-3 – Evaluate the difference

To evaluate the sum $7.3-2.1$, write the numbers vertically with aligned decimal and subtract them as shown below

$\begin{array}{l}\text{\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}}9.9\\ \underset{¯}{-\text{\hspace{0.17em}}5.4\text{\hspace{0.17em}}}\\ \text{\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}}4.5\end{array}$

Thus, the difference of the numbers is $4.5$.