# Math

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i forgot how to solve problems like this...

2x^2-18x=0, x^2=6x+7, 6y^2+5y-6=0

also I need help on this one

SOLVE FOR X CORRECT TO 4 DECIMAL PLACES

x^2+6x+2=0 2x+4=3x^2

• Math -

2x^2-18x=0
try to factor first
2x (x-9) = 0
so x = 0 or x = 9

x^2=6x+7
x^2 -6 x - 7 = 0
(x-7)(x+1) = 0
so x = 7 or x = -1

6y^2+5y-6=0
(6x-1)(x+1) = 0
x = 1/6 or x = -1

x^2+6x+2=0
if you can not factor, complete the square or use the quadratic equation
x = [ -b +/- sqrt (b^2 - 4 a c) ] / 2a
x = [ -6 +/- sqrt (36 - 8) ] / 2
use calculator to 4 places

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