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Algebra Difficulty 1.7 Junior Find the answer

If 100x=9 \sqrt{100-x}=9 , what is the value of x x ?

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

Solution

Since 100x=9 \sqrt{100-x}=9 , then 100x=92=81 100-x=9^{2}=81 , and so x=10081=19 x=100-81=19 .

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