Question

what's the answers
$2n {}^{2} + 9n - 10 - 45 = 0$

Answer 1

2n2 + 9n -10n -45=0
2n2 -1n -45 =0
2n2-(10-9)n-45=0
2n2-10n+9n-45=0
2n(n-5)+9(n-5)=0
(n-5)(2n+9)=0
either
n-5=0
n=5
or
2n+9=0
n=-9/2
n=-4.5.