2x²+√18x=1/4
x²+3√2x/2=1/8
x²+3√2x/2+18/16=1/8+18/16=20/16
(x+3√2/4)²=(±2√5/4)²
x+3√2/4±2√5/4
x=(-3√2-2√5)/4,x=(-3√2+2√5)/4
解方程:2x^2+(根号18)x-1/4=0
2x²+√18x=1/4
x²+3√2x/2=1/8
x²+3√2x/2+18/16=1/8+18/16=20/16
(x+3√2/4)²=(±2√5/4)²
x+3√2/4±2√5/4
x=(-3√2-2√5)/4,x=(-3√2+2√5)/4