candycane2565 Group Title Solve. 2x2 + x = 15. 2 years ago 2 years ago

1. MSMR Group Title

I'm assuming that means $2x ^{2} + x = 15$?

2. candycane2565 Group Title

yes

3. hoblos Group Title

2x2 + x = 15 2x2 + x -15 =0 (2x-5)(x+3)=0 x= 5/2 OR x=-3

4. MSMR Group Title

okay, you'll need to use the quadratic formula: $\frac{-b \pm \sqrt{b ^{2}} - 4ac}{2a}$

5. sfozturk61 Group Title

$2x^2+x-15=0$ $(2x-5)(x+3)=0$ x=2,5 or -3

6. hoblos Group Title

@sfozturk61 2&5 are not solutions 5/2 & -3 are the only solutions **

7. nickup Group Title

Rewrite as 2x^2 +6x - 5x -15. Now factor by grouping 2x(x +3) - 5(x + 3). Factors to (2x- 5)(x+3)= 0 x=5/2 and -3

8. sfozturk61 Group Title

@hoblos I mean 2,5 so 2 and one half = 5/2