One Step Equations Using Subtraction, Addition, Multiplication and Division
How do we solve an equation??? • We have to isolate the variable. • To do this you have to get the variable with a coefficient of 1 alone on one side of the equation. • You can isolate a variable using the properties of equality and inverse operations. • An inverse operation undoes another operation.
Solving an Equation Using Subtraction X + 13 = 27 (You need to isolate x. Start by writing the equation.) X + 13 – 13 = 27 – 13 (Undo addition by subtracting the same number from each side.) What Property is this? X = 14 (Simplify each side of the equation.) Next…You must ALWAYS check your work!!!
Checking your work. • Always check your work and you will make sure you have the correct answer. X + 13 = 27 (Start with the original problem.) 14 + 13 = 27 (Plug in what you found the variable to be.) 27 = 27 (This checks out!!)
Your Turn (Check your work!) 6 = x + 2
Solving an Equation Using Addition -7 = b – 3 (Isolate the variable.) -7 + 3 = b – 3 + 3 (Undo Subtraction by adding the same number to both sides. What Property are you using?) -4 = b (Simplify.) Now you need to check your work. Like we did before.
Your Turn. (Check your work.) m – 8 = -14
Your Turn (Check your work.) ½ = y – 3/2
Solving an Equation using Division 4x = 6.4 (Isolate the variable) (Undo multiplication by dividing the same number from both sides. What Property are you using?) (Simplify each side of the equation.) Check your answer now.
Your turn (check your work) 10 = 15x
Your turn -3.2z = 14
Solving an Equation using Multiplication x/4 = -9 Isolate the variable. Undo division by muliplying. (What property are you using?) Simplify both sides of the equation. Check your work!!!!!
Your turn 19 = r/3 x/-9 = 8
Solving Equations using Reciprocals 4/5m = 28 (Isolate the variable.) (Multiply each side by 5/4, the reciprocal of 4/5.) (Simplify) Check your work!
Your turn 12 = 3/4x