# TWO STEP EQUATIONS WITH NEGATIVE NUMBERS

## About "Two step equations with negative numbers"

Two step equations with negative numbers :

Many real-world quantities such as altitude or temperature involve negative numbers. We solve equations with negative numbers just as we do equations with positive numbers.

## Two step equations with negative numbers - Examples

Example 1 :

To convert a temperature from degrees Fahrenheit to degrees Celsius, first subtract 32. Then multiply the result by 5/9. An outdoor thermometer showed a temperature of -10 °C. What was the temperature in degrees Fahrenheit ?

Solution :

Step 1 :

Let x represent the temperature in degrees Fahrenheit.

Write an equation.

-10  =  (5/9).(x - 32)

Step 2 :

Solve the equation.

Multiply both sides by 9/5

(9/5).(-10)  =  (9/5).(5/9).(x - 32)

-18  =  x - 32

Add 32 to both sides.

-18 + 32  =  x - 32 + 32

14  =  x

Hence, the temperature was 14 degrees Fahrenheit.

Example 2 :

What is the temperature in degrees Fahrenheit of a freezer kept at -20 °C?

Solution :

Step 1 :

Let x represent the temperature in degrees  Fahrenheit.

Write an equation.

-20  =  (5/9).(x - 32)

Step 2 :

Solve the equation.

Multiply both sides by 9/5

(9/5).(-20)  =  (9/5).(5/9).(x - 32)

-36  =  x - 32

Add 32 to both sides.

-36 + 32  =  x - 32 + 32

-4  =  x

Hence, the temperature was -4 degrees Fahrenheit.

Example 3 :

An airplane flies at an altitude of 38,000 feet. As it nears the airport, the plane begins to descend at a rate of 600 feet per minute. At this rate, how many minutes will the plane take to descend to 18,800 feet ?

Solution :

Step 1 :

Let m represent the number of minutes. Write an  equation.

38,000 - 600m  =  18,800

Step 2 :

Subtract 38,000 from both sides.

(38,000 - 600m) - 38,000  =  18,800 - 38,000

-600m  =  -19,200

Divide both sides by -600

(-600m)/(-600)  =  (-19,200)/(-600)

m  =  32

Hence, the plane will take 32 minutes to descend to 18,800 feet.

Example 4 :

Jenny earned 92 of a possible 120 points on a test. She lost 4 points for each incorrect answer. How many incorrect answers did she have?

Solution :

Step 1 :

Let m represent the number of incorrect answers. Write an  equation.

120 - 4m  =  92

Step 2 :

Subtract 120 from both sides.

(120 - 4m) - 120  =  92 - 120

-4m  =  -28

Divide both sides by -4

(-4m)/(-4)  =  (-28)/(-4)

m  =  7

Hence, Jenny had 7 incorrect answers. After having gone through the stuff given above, we hope that the students would have understood "Two step equations with negative numbers".

Apart from the stuff given above, if you want to know more about "Two step equations with negative numbers", please click here

Apart from the stuff given in this section, if you need any other stuff in math, please use our google custom search here.

HTML Comment Box is loading comments... WORD PROBLEMS

HCF and LCM  word problems

Word problems on simple equations

Word problems on linear equations

Word problems on quadratic equations

Algebra word problems

Word problems on trains

Area and perimeter word problems

Word problems on direct variation and inverse variation

Word problems on unit price

Word problems on unit rate

Word problems on comparing rates

Converting customary units word problems

Converting metric units word problems

Word problems on simple interest

Word problems on compound interest

Word problems on types of angles

Complementary and supplementary angles word problems

Double facts word problems

Trigonometry word problems

Percentage word problems

Profit and loss word problems

Markup and markdown word problems

Decimal word problems

Word problems on fractions

Word problems on mixed fractrions

One step equation word problems

Linear inequalities word problems

Ratio and proportion word problems

Time and work word problems

Word problems on sets and venn diagrams

Word problems on ages

Pythagorean theorem word problems

Percent of a number word problems

Word problems on constant speed

Word problems on average speed

Word problems on sum of the angles of a triangle is 180 degree

OTHER TOPICS

Profit and loss shortcuts

Percentage shortcuts

Times table shortcuts

Time, speed and distance shortcuts

Ratio and proportion shortcuts

Domain and range of rational functions

Domain and range of rational functions with holes

Graphing rational functions

Graphing rational functions with holes

Converting repeating decimals in to fractions

Decimal representation of rational numbers

Finding square root using long division

L.C.M method to solve time and work problems

Translating the word problems in to algebraic expressions

Remainder when 2 power 256 is divided by 17

Remainder when 17 power 23 is divided by 16

Sum of all three digit numbers divisible by 6

Sum of all three digit numbers divisible by 7

Sum of all three digit numbers divisible by 8

Sum of all three digit numbers formed using 1, 3, 4

Sum of all three four digit numbers formed with non zero digits

Sum of all three four digit numbers formed using 0, 1, 2, 3

Sum of all three four digit numbers formed using 1, 2, 5, 6