Question

Find the value of the lesser root of x2 - 7x + 12 = 0. A) -3 B) -1 C) 1 D) 3

Answer 1

The answer to your question is D) 3

Answer 2

Answer:

$x_1 = \frac{-(-7) - \sqrt{(-7)^2 -4(1)(12)}}{2(1)}= \frac{7-1}{2}= 3$

$x_2 = \frac{-(-7) + \sqrt{(-7)^2 -4(1)(12)}}{2(1)}= \frac{7+1}{2}= 4$

So then since we want the lesser root the correct answer on this case is:

D) 3

Step-by-step explanation:

For this case we have the followin expression:

$x^2 -7x +12=0$

For this case we can use the quadratic formula in order to solve it, given by:

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

And on this case a = 1, b = -7, c = 12. And if we replace we got:

$x_1 = \frac{-(-7) - \sqrt{(-7)^2 -4(1)(12)}}{2(1)}= \frac{7-1}{2}= 3$

$x_2 = \frac{-(-7) + \sqrt{(-7)^2 -4(1)(12)}}{2(1)}= \frac{7+1}{2}= 4$

So then since we want the lesser root the correct answer on this case is:

D) 3