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Popular >

a^2-4a-21=0

Solution

a^{2} - 4 a - 21 = 0

Solution

a = 7, a = - 3

Solution steps

a^{2} - 4 a - 21 = 0

Solve with the quadratic formula

a_{1, 2} = \frac{- ( - 4 ) \pm ( - 4 ) ^{2} - 4 \cdot 1 \cdot ( - 21 )}{2 \cdot 1}

(- 4)^{2} - 4 \cdot 1 \cdot (- 21) = 10

a_{1, 2} = \frac{- ( - 4 ) \pm 10}{2 \cdot 1}

Separate the solutions

a_{1} = \frac{- ( - 4 ) + 10}{2 \cdot 1}, a_{2} = \frac{- ( - 4 ) - 10}{2 \cdot 1}

a = \frac{- ( - 4 ) + 10}{2 \cdot 1} : 7

a = \frac{- ( - 4 ) - 10}{2 \cdot 1} : - 3

The solutions to the quadratic equation are:

a = 7, a = - 3

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Frequently Asked Questions (FAQ)

What are the solutions to the equation a^2-4a-21=0 ?
The solutions to the equation a^2-4a-21=0 are a=7,a=-3
Find the zeros of a^2-4a-21=0
The zeros of a^2-4a-21=0 are a=7,a=-3