e q u a t i o n s

 

 

Equations 9

Simplifying Expressions in Equations

After doing this page, try the Equations 9 Quiz.

RECAP: We have been introduced to variables in equations. Now let's look at simplifying some equations with addition and subtraction.

Here is a simple one to start. In this equation we must simplify the equation to find the value of the variable. The equation is two times x plus four plus three times x plus five equals forty-eight.

2(x + 4) + 3(x + 5) = 48
2x + 8 + 3x + 15 =48
5x + 23 =48
5x = 25

2(5 + 4) + 3(5 + 5) = 48
2(9) + 3(10) = 48
18 + 30 = 48

Here is another example, four times x minus seven minus three times x plus five equals two times x plus five plus three times x minus ten.

 

4(x - 6) -3(x + 5) = 2(x + 3) + 2(x - 6)
4x - 24 - 3x - 15 = 2x + 6 + 2x - 12
x - 39 = 4x - 6
-33 = 3x
-11 = x

4(-11-6) -3(-11 +5) = 2(-11 +3) + 2(-11 -6)
4(-17) -3(-6) = 2(-8) + 2(-17)
-68 +18 = -16 -34
-50=-50

 

Algebra Main Page Positive & Negative Numbers Addition & Subtraction of Positive & Negative Numbers Multiplication of Positive & Negative Numbers Division of Positive & Negative Numbers Order of Operations
Exponents Scientific Notation Equations 1 Equations 2 Equations 3

Equations 4

Equations 5

Equations 6 Equations 7 Equations 8 Equations 9