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find the zeros of each equation?
2x^2+8x-30=x+3
please explain how to do it step by step, for the record I am really bad at quadratics, so don't hold back on how simple your steps are.
Thanks
2 Answers
- RogueLv 78 years agoFavorite Answer
via completing the square:
2x^2+8x-30=x+3
step on rearrange so as the 'x's are on one side and the constants are the other
=> 2x^2 + 7x = 33
now that divide both sides by 2 to get the coefficient of the x^2 term to equal 1
=> x^2 + (7/2)x = 33/2
now square half of the coefficient of the x^1 term and add it to both sides
=> x^2 + (7/2)x + (7/4)^2 = 33/2 + (7/4)^2
you now have the pattern of x^2 + bx + (b/2)^2 = (x + b/2)^2
=> (x + 7/4)^2 = 313/16
now take the square root of both sides
=> x + 7/4 = ±√(313)/4
now isolate the x
=> x = (-7-√313)/4 or (√313 - 7)/4
- Anonymous8 years ago
ok i so i will find it for you
there is one zero in 30 which is 0 and thats it!
easy