Introduction to Solving Linear Equations

8.1 Solve Equations Using the Subtraction and Addition Properties of Equality

8.2 Solve Equations Using the Division and Multiplication Properties of Equality

8.3 Solve Equations with Variables and Constants on Both Sides

8.4 Solve Equations with Fraction or Decimal Coefficients

Step 1. Substitute the number for the variable in the equation.

Step 2. Simplify the expressions on both sides of the equation.

Step 3. Determine whether the resulting equation is true.

If it is true, the number is a solution.

If it is not true, the number is not a solution.

Subtraction Property of Equality

For all real numbers a, b, and c,

if a = b then a−c=b−c.

Addition Property of Equality

For all real numbers a, b, and c,

if a = b then a+c=b+c.

3x+5=23.

ⓐ6

ⓑ235

n−18=31

9c=144

4y−8=16

−8x−15+9x−1=−21

−15a=120

x+3.8=8.2

10y=−5y+60

8n+2=6n+12

−5(2x+1)=45

https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:solve-equations-inequalities/x2f8bb11595b61c86:linear-equations-variables-both-sides/e/linear_equations_3