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mojhsa [17]
3 years ago
6

Solve the quadratic equation by square roots: 1. 4x²= 81 2. (4x-3)²+7=39

Mathematics
1 answer:
Nataly [62]3 years ago
7 0

Answer:

see explanation

Step-by-step explanation:

(1)

given

4x² = 81 ( divide both sides by 4 )

x² = \frac{81}{4} ( take the square root of both sides )

x = ± \sqrt{\frac{81}{4} } = ± \frac{9}{2}

---------------------------------------------------------------------

(2)

subtract 7 from both sides

(4x - 3)² = 32 ( take the square root of both sides )

4x - 3 = ± \sqrt{32} = ± 4\sqrt{2}

Add 3 to both sides

4x = 3 ± 4\sqrt{2} ( divide both sides by 4 )

x = \frac{3}{4} ± \sqrt{2}

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Step-by-step explanation:

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