Urgent Please.....

Algebra Level 1

If three times a positive number is subtracted from the square of the number, the result is $10$ . Find the number.

2 solutions

Victor Loh
Jul 9, 2014

Let the positive number be $a$ . Then $a^2-3a=10\implies a^2-3a-10=0$ . Upon factorisation, we find that $a^2-3a-10=(a+2)(a-5)=0$ , which yields

$a+2=0\implies a=-2$ or $a-5=0\implies a=5.$

Since $a$ is positive, we have $a=\boxed{5}$ and we are done.

NICE : } me too solved in the same way.....

PUSHPESH KUMAR - 6 years, 10 months ago

Bala Ila
Jul 9, 2014

Let unknown be x. X^2-3X=10. X^2 - 3X -10=0 Solve this quadratic equation. X=5 and X=-2.