+0

# x^(2) - 6x = 1/2x + 42

0
341
1

x^(2) - 6x = 1/2x + 42

Find x

Guest Aug 16, 2017
#1
+349
0

For this, we need to transorm the eq. to standard form:

$$x^2-6x=\frac{1}{2}x+42$$

$$x^2-\frac{13}{2}x-42=0$$

Now to use the quadratic formula:

$$a=1$$

$$b=-\frac{13}{2}$$

$$c=-42$$

$$x = {-b \pm \sqrt{b^2-4ac} \over 2a}$$

$$x = {-(-\frac{13}{2}) \pm \sqrt{(\frac{13}{2})^2-4(1)(-42)} \over 2(1)}$$

$$x = \frac{\frac{13}{2} \pm \sqrt{210+{1 \over 4}}}{2}$$

$$x = {{13 \over 2}\pm(14+{1 \over 2})\over 2}$$

$$x = {10+{1\over2}, -4}$$

Mathhemathh  Aug 16, 2017