In chemistry, we use equations that express the relationship between certain variables. Let’s

look at how we would solve for x in the following equation:

2x + 8 = 14

Our overall goal is to rearrange the items in the equation to obtain x on one side.

- Place all/ike temJS on one side. The numbers 8 and 14 are like terms. To remove

the 8 from the left side of the equation, we subtract 8. To keep a balance, we need to

subtract 8 from the 14 on the other side.

2x + .8′ – .8′ = 14 – 8

2x = 6 - Isolate the variable you need to solve for. In this problem, we obtain x by dividing

both sides of the equation by 2. The value of x is the result when 6 is divided by 2.

Zr 6 z = 2

X = 3 - Check your answer. Check your answer by substituting your value for x back into

the original equation.

2(3) + 8 = 14

6 + 8 = 14

14 = 14 Your answer x = 3 is correct.

Summary: To solve an equation for a particular variable, be sure you perform the same

mathematical operations on both s ides of the equation.

If you eliminate a symbol or number by subtracting, you need to subtract that same

symbol or number from both sides.

If you eliminate a symbol or number by adding, you need to add that same symbol or

number to both sides.

If you cancel a symbol or number by dividing, you need to divide both sides by that

same symbol or number.

If you cancel a symbol or number by multiplying, you need to multiply both s ides by

that same symbol or number.

When we work with temperature, we may need to convert between degrees Celsius and

degrees Fahrenheit using the following equation: - TF = 1.8(Tc) + 32

To obtain the equation for converting degrees Fahrenheit to degrees Celsius, we subtract

32 from both sides.

TF = 1.8(Tc) + 32

TF – 32 = 1.8(Tc) + n – n

TF – 32 = 1.8(Tc)

To obtain Tc by itself, we divide both sides by 1.8.

Tr – 32 M!'(Tc)

— = –= Tc

1.8 .k8′