Question

solve 5x²-7x-6=0 by completing square method​

Answer 1

Answer:

√ 7/5

Step-by-step explanation:

= 5x^2 - 7 x 6= 0

= 5x^2 - 7 = 0

= 5x^2 = 7

= x^2 = 7/5

= x= √7/5

hope it helps...

Answer 2

Given equation : $5x^2-7x-6=0$

Dividing the equation by 5 on both sides :

$x^2-\frac{7}{5}x-\frac{6}{5}=0\\ \\x^2-\frac{7}{5}x=\frac{6}{5}$

Adding both sides by (7/10)² :    

$x^2 - \frac{7}{5}x + \frac{49}{100} = \frac{6}{5} +\frac{49}{100}\\ \\ ( x -\frac{7}{10} )^2 = \frac{169}{100}$

Taking under-root both sides :

x - 7/10 = ± 13/10

⇒ x = + 13/10 + 7/10 = 20/10 = 2

Or ,

⇒ x = -13/10 + 7/10 = -6/10 = -3/5

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Explanation for addition of (7/10)² :

The term which is to be added for making (a - b)² or (a + b)² should be found by using the following formula :

= ( 1/2 × Coefficient of x ) ²

= ( 1/2 × 7/5 ) ²

= ( 7/10 ) ²

= ( 49/100 )