Use algebra tiles to solve x + 2 = 4 + = = x = 2
To solve an addition equation, subtract the same number from each side so that the variable is by itself on one side (isolated). This process is called using the inverse operation (subtraction is the inverse or opposite operation of addition).
Collecting Example: You gave away 2 conch shells from your collection and now you have 5 conch shells left. How many conch shells did you have at the start? An equation that represents this situation is x – 2 = 5, where x is the number of conch shells you had in your collection at the start.
After giving away 2 conch shells, you have 5 conch shells. x – 2 = 5 To find the value x you had before subtracting 2, you can add 2 to undo the subtraction. 5 + 2 = x x = 7 Check: x – 2 = 5 7 -2 = 5 5 = 5
To solve a subtraction equation, add the same number to each side so that the variable is by itself on one side (isolated). This process is called using the inverse operation (addition is the inverse or opposite operation of subtraction).
To solve an equation, try to get the variable by itself on one side of the equation. You can use inverse operations to undo the process in order to isolate the variable. To solve a multiplication equation, divide each side by the number that the variable is multiplied by. To solve a division equation, multiply each side by the divisor.
Cheerleading: In a local cheerleading competition, a team is awarded points in 3 categories. The mean of the teams scores for the 3 categories is 21. Write and solve a division equation to find t, the total number of points the team earns.