Question

5n²-125n+ 720=0, find the value of n.
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Answer 1

Step-by-step explanation:

$let \: n = x...... \\ \\ 5 {x}^{2} - 125x + 720 = 0 \\ \\ dividing\: both \: sides \: by \: 5..... \\ \\w e \: get... {x}^{2} - 25x + 144 = 0 \\ \\ {x}^{2} - 16x - 9x + 144 = 0 \\ \\ x(x - 16) - 9(x - 16) = 0 \\ \\ (x - 9)(x - 16) = 0 \\ \\ x = 9..........x = 16$

Answer 2

Answer:

5n^2 - 125n + 720= 0

or, 5 (n^2 - 25n + 144) = 0

or, n^2 - 25n + 144 =0

or, n^2 - (16+9) + 144 =0

or, n^2 - 16n - 9n + 144 =0

or, n (n-16) -9 (n-16)=0

or, (n-16)(n-9)=0

Now ,

Either Or

n-16=0 n-9=0

n=16 n=9