Question

find the roots of x square - 7 x + 10 is equal to zero by quadratic

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Answer 1

Question:

x² - 7x + 10 = 0

Sol:

x² - 5x - 2x + 10 = 0

x ( x - 5 ) -2 ( x - 5 ) = 0

( x - 2 ) ( x - 5 ) = 0

x - 2 = 0 , x - 5 = 0

x = 2 , x = 5

Answer 2

Solution :

Given Equation,

$\sf \: {x}^{2} - 7x + 10 = 0$

On comparing with ax² + bx + c = 0,

a = 1,b = - 7 and c = 10

Discriminant,D : b² - 4ac

» D = (-7)² - 4(1)(10)

» D = 49 - 40

»D = 9

Now,

$\sf \: x = \dfrac{ - b \pm \sqrt{d} }{2a} \\ \\ \longrightarrow \: \sf \: x = \dfrac{ - ( - 7) \pm \sqrt{9} }{2(1)} \\ \\ \longrightarrow \: \sf \: x = \dfrac{7 \pm \: 3}{2} \\ \\ \longrightarrow \: \boxed{ \boxed{ \sf{x = 5 \: or \: \: 2}}}$