Answers

2014-08-03T16:21:39+08:00
X²+7x+10=0 (x + 5) (x + 2) = 0 x = -5 , -2
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2014-08-04T20:27:10+08:00
X²+7x+10 = 0
x²+7x = -10
x+7x+ (7/2)² = (x+7/2)² =   ( 7/2)² - 10           
when completing the square you have added 49/4 to
the left side of the equation,you must also add 49/4 to
the right of the equation to balance up
              =  49/4- 10 =  9/4
x+7/2 = + or -√9/4 =  3/2
x    =      3/2-7/2 =  - 4/2 =   -2  or  -3/2 -7/2 = -5


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