Chapter 7 Equations

Simplify Expressions

100

-8x * -3x

24x²

200

0.5m * 0.5m *0.5m

0.125m³

300

81x³y⁵z * 2x⁶y²z²

162x⁸y⁷z³

400

(125a⁵b³c⁹) / (25a³bc⁷)

5a²b²c²

500

(-42d⁴g³) / (66d⁴g⁷)

Use positive exponents only.

-7 / (11g⁴)

Solve Basic Equations

100

5x+8=63

11

200

2x + 5x = 105

15

300

-5x + 1/2 = 28

-5.5

400

The voltage E is related to the number of windings w of wire around the core by the equation E=50W. How many windings will produce a voltage of 725 V?

14.5

500

Cole's truck was speeding 8 mph over the speed limit (35 mph). He continued this rate for 2 hours and 15 minutes. How far did he travel? 

96.75 miles

Multi-Step Equations

100

2(4m - 6) = 12m + 2

-3.5

200

19x -5(3x-2)=28

4.5

300

The fire damage potential D of a forest is given by the formula D=2A+4 where A is the average age (in years) of the brush in the forest. If D=20, find the average age of the brush.

8 years

400

An appliance repair shop charges $70 for the first hour of labor and $65 for each additional hour. The total labor charge for an air conditioning system installation was $525. Write an equation for finding the total repair time. Then solve the equation.

70+65x=525

x=7 

8 total hours

500

The pressure P (in pounds per square inch or psi) on a submerged body in wastewater is given by P=0.520D+14.7, where D is the depth in feet. At what depth is the pressure 70 psi?

106.35 feet

Scientific Notation

100

Write in scientific notation:   89,000,000

8.9 x 10⁷

200

Write in standard form:   8 x 10^-3

0.008

300

Google bought youTube for $1,650,000,000. Write this in scientific notation 

1.65 x 10⁹

400

The 2004 Indonesian earthquake slowed the rotation of Earth, making the length of a day 0.00000268 second shorter. Write this number in scientific notation.

2.68 x 10^-6

500

Rewrite the following numbers in scientific notation and calculate the answer in scientific notation. 

0.0000088 / 3200    

8.8 x 10^-6 / 3.2 x 10³

2.75 x 10^-9