Question

solve
8x^2-22x-21=0 solve this by completing square method

Answer 1

Question- solve=8x^2-22x-21=0 solve by completing square method

solution- Given quadratic equation is 8x^2-22x-21=0 on comparing with standard from of quadratic equation ax^2+bx+c=0

here A=8 , b=-22 , c=-21

ac = 8×-21=-168

• c have negative sign so we have to find the factor of 168 whose difference is -22
• such factor 28 and 6
• 8x^2-22x-21=0
• 8x^2-28x+6x-21=0
• 4x(2x-7)+3(2x-7)=0
• (4X+3) (2X-7)=0
• (4x+3)=0 or (2x-7)=0
• 4x=0-3 or 2x=0+7
• x=-3/4 x=7/2
• hence, root of equation 8x^2-22x-21=0
• are -3/4 and 7/2

i hope you gave a help

"please make me brillent"

Answer 2

x=-3/4, 7/2

Given,

8x^2-22x-21=0

To find,

8x^2-22x-21=0 solve this by completing square method

Solution

8x^2-22x-21=0 solve this by completing square method

Solution Step by Step:

The quadratic equation ax2+bx+c=0's standard form is

8x^2-22x-21=0

8x^2-28x+6x-21=0

4x(2x-7)+3(2x-7)=0

(4x+3)(2x-7)=0

4x+3=0

4x=-3

x=-3/4

2x-7=0

2x=7

x=7/2

Hence x=-3/4, 7/2

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