To solve an equation:
1. Remember, your mission is to get the variable all by itself. .:Cue Mission Impossible theme:.
2. To do this, use the inverse operation. Ask yourself, "What's happening to the variable?" and then
do the opposite of that to both sides. Remember that addition and subtraction are opposites, and
multiplication and division are opposites.
3. Your equation will now tell you what the variable equals.
Examples:
6 + y = 17 ---> What's happening to the variable? We're adding 6 to it. The inverse operation
would be to subtract 6. DON'T FORGET - YOU MUST DO THE SAME
TO BOTH SIDES.
6 + y - 6 = 17 - 6 ---> Solve both sides of the equation.
y = 11
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-2 = a - 10 ---> What's happening to the variable? We're subtracting 10 from it. The inverse
operation would be to add 10.
-2 + 10 = a - 10 + 10 ---> Solve both sides.
8 = a
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3x = -15 ---> Since we're multiplying the variable by 3, the inverse operation would be to divide
by 3.
3x = -15 ---> Remember, the fraction bar means "divided by."
3 3
x = -5
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m = 3 ---> Since we're dividing the variable by 9, the inverse operation would be to multiply by 9.
9
9 x m = 3 x 9 ---> Don't forget, a 9 on top and on bottom cancel each other out.
9
m = 27
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Well, folks, there you have it. Just make sure you:
1. Use the inverse operation
2. Do the same thing to both sides
3. Get the variable by itself
4. Check your answer by plugging that value into the original equation (in place of the variable)
