How do you solve $2 q + q^{2} = 15$ $2q+q^2=15$ ?

Question

How do you solve $2 q + q^{2} = 15$ $2q+q^2=15$ ?

1 Answer

Impact of this question

2203 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-06-17T03:59:38

$q = 3, q = - 5$ $color(red)( q=3, q=-5$

Explanation:

$2 q + q^{2} = 15$ $2q+q^2=15$
$q^{2} + 2 q - 15 = 0$ $q^2 + 2q-15=0$

We can first factorise this expression and then proceed towards finding the solution.

Factorising by splitting the middle term

$q^{2} + 5 q - 3 q - 15 = 0$ $q^2 + 5q - 3q -15=0$
$q (q + 5) - 3 (q + 5) = 0$ $q(q + 5) - 3(q +5)=0$
$(q - 3) (q + 5) = 0$ $(q - 3)(q +5)=0$

Equating with zero :
$q - 3 = 0, q = 3$ $q-3 = 0, q=3$
$q + 5 = 0, q = - 5$ $q+5 = 0 , q=-5$
Thus the solutions are:
$q = 3, q = - 5$ $color(red)( q=3, q=-5$

Science

Math

Humanities

... and beyond

How do you solve $2 q + q^{2} = 15$ $2q+q^2=15$ ?

1 Answer

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

How do you solve 2q+q2=152q+q^2=15?

1 Answer

Explanation:

Related questions

Impact of this question

How do you solve $2 q + q^{2} = 15$ $2q+q^2=15$ ?