How do you solve the quadratic using the quadratic formula given $n^{2} = 9 n - 20$ $n^2=9n-20$ ?

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Answer 1 · 2016-11-04T06:54:06

$n = 4$ $n=4$ and $n = 5$ $n=5$

$n^{2} = 9 n - 20$ $n^2=9n-20$

Take all the terms to the left.

$n^{2} - 9 n + 20 = 0$ $n^2-9n+20=0$

Factorise the equation.

$n^{2} - 5 n - 4 n + 20 = 0$ $n^2-5n-4n+20=0$

$n (n - 5) - 4 (n - 5) = 0$ $n(n-5)-4(n-5)=0$

$(n - 4) (n - 5) = 0$ $(n-4)(n-5)=0$

$n - 4 = 0$ $n-4=0$ and $n - 5 = 0$ $n-5=0$

$n = 4$ $n=4$ and $n = 5$ $n=5$

How do you solve the quadratic using the quadratic formula given n2=9n−20n^2=9n-20?