.
Solve
= 35.
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Introduce new variable y =
.
Then the given equation takes the form
y*(2+y) = 35.
To solve it formally, reduce it to the standard form of a quadratic equation or by factoring.
Also, the roots can be easily guessed MENTALLY.
In any case, the roots of equation (1) are y = 5 or y = -7.
Since we admit only positive values for square roots, the original equation has only one solution x = 5^2 = 25. ANSWER
Solved.