Question

find the root of the following quadratic equation by factorisation x square - 3 x minus 10 is equal to zero​

Answer 1

Find the roots of x² - 3x -10 = 0

Solution-.

${x}^{2} - 3x - 10 \\ \\ {x}^{2} - 5x + 2x - 10 = 0 \\ \\ x(x - 5) + 2(x - 5) = 0 \\ \\ (x + 2) \: \: \: \: \: \: \: \: \: \: \: (x - 5) \\ \\ x + 2 = 0 \\ \\ x = - 2 \\ \\ \\ \\ x - 5 = 0 \\ \\ x = 5$

2nd method .

By completing square method

$a = > 1 \\ \\ b = > - 3 \\ \\ c = > - 10$

$\color{red} \boxed{d = {b}^{2} - 4ac}$

$d = > ( - 3 {)}^{2} - 4 \times 1 \times - 10 \\ \\ d = > 9 + 40 \\ \\ d = > 49$

$\color{blue} \boxed{x = > \frac{ - b + - \sqrt{d} }{2a}}$

$x = > \frac{ - (- 3 )+ - \sqrt{49} }{2 \times 1} \\ \\ x = > \frac{ 3 + \sqrt{49} }{2} \: \: \: \: \: \: \: \: \: \: x = > \frac{ 3 - \sqrt{49} }{2} \\ \\ x = > \frac{ 3 + 7}{2} \: \: \: \: \: \: \: \: \: x = > \frac{ 3 - 7}{2} \\ \\ x = > \frac{10}{2} \: \: \: \: \: \: \: \: x = > \frac{ -4}{2} \\ \\ x = > 5 \: \: \: \: \: \: \: \: \: \: x = > - 2$

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Note...

You will choose any method from above to find factors.

Hope it's helps you ☺️✨✨✨