Chapter 8, Problem 7CR

To determine

An equation and how many granola bars Rosa can make if she has 336 ounces of dough

Answer to Problem 7CR

The equation is $4.8x=336$

She can make granola bars are $x=70$ .

Explanation of Solution

Given:

Rosa is baking granola bars for her friends. Each bar required 4.8 ounces of dough and she has 336 ounces of dough

Concept Used:

• To get rid of a number in addition from one side, subtract the same number from both sides of equal sign.
• To get rid of a number in subtraction from one side, add the same number both sides of equal sign.
• To get rid of a number in multiplication from one side, divide the same number from both sides of equal sign.
• To get rid of a number in division from one side, multiply the same number both sides of equal sign.

Rules of Addition/ Subtraction:

• Two numbers with similar sign always get added and the resulting number will carry the similar sign.
• Two numbers with opposite signs always get subtracted and the resulting number will carry the sign of larger number.

Rules of Multiplication/ Division:

• The product/quotient of two similar sign numbers is always positive.
• The product/quotient of two numbers with opposite signs is always negative.

Calculation:

In order to find the number of bars she makes

Let x be the number of bars she can make

Thus, the equation is $4.8x=336$

Here to isolate x on left side, first divide both sides by $4.8$ and then simplify further as shown below,

  $\begin{array}{c}4.8x=336\\ \frac{4.8x}{4.8}=\frac{336}{4.8}\\ x=70\end{array}$

Thus, she can make granola bars are $x=70$ .