Question

I need help factoring to solve quadratics.2z^2-21z-36?How do I do this?

Answer 1

\[x = \frac{ -b \pm \sqrt{b^{2}-4ac} }{ 2a }\]

Where

Answer 2

a = 2z
b = -21
c= -36

Answer 3

To factor a trinomial of the type
ax^2 + bx + c,
follow these steps.
1. Multiply ac together.
2. Find two factors of ac that add to b. Call the factors p and q.
3. Break up the middle term, bx, into the two parts, px and qx.
4. Rewrite the trinomial as ax^2 + px + qx + c
5. Factor the ploynomial above by parts. First factor a common factor out of the first two terms. Then factor a common factor out the last two terms.
6. Then factor out the common facotr.

Answer 4

Now that you see the method, let's do it step by step.
1. ac = 2(-36) = -72

Answer 5

2. -72 = (-24)(3); -24 + 3 = -21. Our p & q are -24 and 3

Answer 6

3. -21z = -24z + 3z
4. 2z^2 - 24z + 3z - 36

Answer 7

5. 2z(z - 12) + 3(z - 12)
6. (z - 12)(2z + 3)