Using the quadratic formula to solve 7x2 – x = 7, what are the values of x?

Question

asked Sep 17, 2019 229k views

2 Answers

Yehor Krivokon · Answer 1 · 2019-09-22T17:50:55+0000

Answer:

x = 1.074

x = -0.931

Explanation:

The given expression is 7x² - x = 7

7x² - x - 7 = 0

Now we apply the quadratic formula in the given expression to find the value of x.

Since quadratic formula is

$x=\frac{b\pm \sqrt{b^(2)-4ac}}{2a}$

So we put the value of b = -1, a = 7 and c = -7

x
$=\frac{+1\pm \sqrt{(-1)^(2)-4(7)(-7)}}{2(7))}$

$=(1\pm √(1+196))/(14)$

$=(1\pm √(197))/(14)$

$x=(1\pm 14.035)/(14)$

x = 1.074

x = -0.931