What are the solutions to the equation (n(n-3))/2 =9 ?

The solutions to the equation (n(n-3))/2 =9 are n=6,n=-3

Find the zeros of (n(n-3))/2 =9

The zeros of (n(n-3))/2 =9 are n=6,n=-3

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\frac{n ( n - 3 )}{2} = 9

n = 6, n = - 3

Solution steps

\frac{n ( n - 3 )}{2} = 9

Multiply both sides by

2

n (n - 3) = 18

Expand

n (n - 3) : n^{2} - 3 n

n^{2} - 3 n = 18

Move

18

to the left side

n^{2} - 3 n - 18 = 0

Solve with the quadratic formula

n_{1, 2} = \frac{- ( - 3 ) \pm ( - 3 ) ^{2} - 4 \cdot 1 \cdot ( - 18 )}{2 \cdot 1}

(- 3)^{2} - 4 \cdot 1 \cdot (- 18) = 9

n_{1, 2} = \frac{- ( - 3 ) \pm 9}{2 \cdot 1}

Separate the solutions

n_{1} = \frac{- ( - 3 ) + 9}{2 \cdot 1}, n_{2} = \frac{- ( - 3 ) - 9}{2 \cdot 1}

n = \frac{- ( - 3 ) + 9}{2 \cdot 1} : 6

n = \frac{- ( - 3 ) - 9}{2 \cdot 1} : - 3

The solutions to the quadratic equation are:

n = 6, n = - 3

(x - 5) (x + 2) = 12

(2 x + 2)^{2} = (2 x - 2)^{2} + (2 x)^{2}

25 x^{2} + 9 = - 30 x

- 2 x^{2} + 8 x - 14

l, A = l^{2}

What are the solutions to the equation (n(n-3))/2 =9 ?
The solutions to the equation (n(n-3))/2 =9 are n=6,n=-3
Find the zeros of (n(n-3))/2 =9
The zeros of (n(n-3))/2 =9 are n=6,n=-3