Question

find the zeroes of the quadratic polynomial 8xsquare-21-22x.

Answer 1

8x^2 - 21 - 22x
8x^2 - 22x - 21
8x^2 - 28x + 6x - 22x
(8x^2 - 28x) + (6x - 22x)
4x ( 2x - 7) + 3 (2x - 7) 
(4x + 3) (2x - 7)
Now, 
4x + 3 = 0x = -3/4
2x - 7 = 0x = 7/2
Comparing 8x^2 - 22x - 21 with ax^2 + bx + c 
a = 8 , b = -22 , c = -21
Alpha ( @ ) = -3/4Beta ( ß ) = 7/2
Sum of zeroes ( @ + ß ) = - b/a
-3/4 + 7/2 = - ( - 22) / 8
-3 + 14 /4= 22/8
11/4 = 11/4 

Product of zeroes ( @ × ß ) = c / a
- 3/4 × 7/2 = -21 / 8
-21 / 8 = -21/8


Hence, Verified! 
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Hope it helps...!!