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Matt the Magician had 4 times as many black balloons as purple balloons.
After he gave away 9 black balloons, he found that he had an equal number
of black and purple balloons left. How many balloons did Matt the Magician have at first?
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x = # of purple balloons;
4x = # of black balloons.
Equation
4x - 9 = x
Solution
4x - x = 9
3x = 9
x = 9/3 = 3.
ANSWER. 3 purple balloons and 4*3 = 12 black balloons.
Solved.