SOLUTION: Can you help me use the quadratic equation for these problems 6x=2-5x^2 X^2+6x=-8 X=6x^2-3

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Question 1021841: Can you help me use the quadratic equation for these problems
6x=2-5x^2
X^2+6x=-8
X=6x^2-3

Answer by Cromlix(4381) About Me  (Show Source):
You can put this solution on YOUR website!
Hi there,
6x=2-5x^2
Rearrange into y = ax^2 + bx + c
5x^2 + 6x - 2 + 0
You must use the quadratic formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a = -5 b = -6 c = 2

x+=+%286+%2B-+sqrt%28+76+%29%29%2F%28-10%29+
..........
x+=+%286+%2B+sqrt%2876+%29%29%2F%28-10%29+
or
x+=+%286+-+sqrt%2876+%29%29%2F%28-10%29+
..........
x = -1.47 or 0.27
--------------------
x^2 + 6x = -8
x^2 + 6x + 8 = 0
(x + 4)(x + 2) = 0
x + 4 = 0
x = -4
x + 2 = 0
x = -2
--------------------
x = 6x^2 - 3
6x^2 - x - 3 = 0
Use quadratic formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a = 6 b = -1 c = -3

x+=+%281+%2B-+sqrt%28+1%2B72+%29%29%2F%2812%29+
x+=+%281+%2B-+sqrt%28+73+%29%29%2F%2812%29+
...................
x+=+%281+%2B+sqrt%28+73+%29%29%2F%2812%29+
or
x+=+%281+-+sqrt%28+73+%29%29%2F%2812%29+
.....................
x = 0.8 or -0.63
Hope this helps :-)