Creating Equations with Whole Numbers

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Basic Math › Creating Equations with Whole Numbers

Questions 1 - 7
1

Dr. Jones charges a $50 flat fee for every patient. He also charges his patients $40 for every 10 minutes that he spends with him. If Mrs. Smith had an appointment that lasted 30 minutes, how much did she have to pay Dr. Jones?

$170

$90

$120

$200

Explanation

We can express Dr. Jones's rate in a linear equation:

Since Mrs. Smith's appointment lasted 30 minutes, we have 3 10-minute intervals. Then, we can plug in that number into our above equation to find out how much the appointment cost.

2

What is the solution of that satisfies both equations?

Explanation

Reduce the second system by dividing by 3.

Second Equation:

We this by 3.

Then we subtract the first equation from our new equation.

First Equation:

First Equation - Second Equation:

Left Hand Side:

Right Hand Side:

Our result is:

3

Jimmy had in lunch money for school. Everyday he spends for food and drinks. What is the expression that shows how much money will he have after each day, where is the days, and is the total amount of money left?

Explanation

Jimmy starts off with $60, and spends $3.50 everyday.

This means that he will have $56.50 after day 1, $53 after day 2, and so forth.

Only one equation satisfies this scenario. The rest are irrelevant.

4

What is the solution of for the two systems?

Explanation

We first multiply the second equation by 4.

So our resulting equation is:

Then we subtract the first equation from the second new equation.

Left Hand Side:

Right Hand Side:

Resulting Equation:

We divide both sides by -15

Left Hand Side:

Right Hand Side:

Our result is:

5

Roman is ordering uniforms for the tennis team. He knows how many people are on the team and how many uniforms come in each box. Which equation can be used to solve for how many boxes Roman should order?

b = number of students ÷ number of uniforms per box

b = number of boxes ÷ number of uniforms per box

b = number of students x number of uniforms per box

b = number of boxes x number of uniforms per box

b = number of students - number of uniforms per box

Explanation

The total number of uniforms needed equals the number of students divided by the number of uniforms per box.

6

What is the solution of for the two systems of equations?

Explanation

We first add both systems of equations.

Left Hand Side:

Right Hand Side:

Our resulting equation is:

We divide both sides by 3.

Left Hand Side:

Right Hand Side:

Our resulting equation is:

7

What is the solution of for the systems of equations?

Explanation

We add the two systems of equations:

For the Left Hand Side:

For the Right Hand Side:

So our resulting equation is:

Divide both sides by 10:

For the Left Hand Side:

For the Right Hand Side:

Our result is:

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