SOLUTION: please help me solve this! solve x^2 +7x-4=0

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Question 470543: please help me solve this! solve x^2 +7x-4=0
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 +7x-4=0
Find the roots of the equation by quadratic formula

a= 1 b= 7 c= -4

b^2-4ac= 49 - 16
b^2-4ac= 65
sqrt%28%0965%09%29= 8.06
x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=( -7 + 8.06 )/ 2
x1= 0.53 5/9
x2=( -7 -8.06 ) / 2
x2= -7.53 -68/9
Ignore negative value
x = 0.53 mph LCD = speed
m.ananth@hotmail.ca