Question

$5x { }^{2} + x - 7$
​

Answer 1

Answer

$\tt{5x^{2} + x - 7}$

By quadratic formula: $\tt{\tiny{\frac{-b \pm \sqrt{b^{2} - 4ac}}{2a}}}$

=> $\tt{\frac{-1 \pm \sqrt{(-1)^{2} - 4(5)(-7)}}{2(5)}}$

=> $\tt{\frac{-1 \pm \sqrt{141}}{10}}$

The two roots :- $\tt{\frac{-1 + \sqrt{141}}{10}}$

And

$\tt{\frac{-1 - \sqrt{141}}{10}}$

Answer 2

Answer: $\tt{\frac{-1 \pm \sqrt{141}}{10}}$

Step by Step explanation:

Given equation : 5x² + x - 7 = 0

In this equation, as we observe, we can't use simple factorisation method for solving and finding out the zeroes; therefore, we'll use a more time efficient method of the Quadratic Formula.

The quadratic formula: $\sf{\frac{-b \pm \sqrt{b^{2} - 4ac}}{2a}}$

Here, in this question:

a = 5

b = 1

c = (-7)

Put the values and solve it further:

x =》 $\sf{\frac{-1 \pm \sqrt{(-1)^{2} - 4(-7)(5)}}{2(5)}}$

Solve this formed equation further:

x =》 $\sf{\frac{-1 \pm \sqrt{1 - 140}}{10}}$

x =》 $\sf{\frac{-1 \pm \sqrt{141}}{10}}$

Here you get the zeroes.