Question

EXERCISE 4.2
1. Find the roots of the following quadratic equations by factorisation:
(i) x2 – 3x - 10 = 0
(ii) 2x2 + x-6=0
(iii) V2 x? + 7 x+5^2 = 0
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Answer 1

Answer:

x+1=0

x=-1

or

x-1=0

x=1

use it

Answer 2

Answer:

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

$2 {x}^{2} + x - 6 = 0 \\ 2 {x}^{2} + 4x - 3x - 6 = 0 \\ 2x(x + 2) - 3(x + 2) = 0 \\ (2x - 3)(x + 2) = 0 \\ x = \frac{ 3}{2} \: \: x = - 2$