x²+0.5x-0.78=0怎么解?
问题描述：
x²+0.5x-0.78=0怎么解?
答
∵x²+0.5x-0.78=(x+0.25)^2-0.8425=0∴(x+0.25)^2=0.8425,∴x≈0.9179-0.25=0.6679
x²+0.5x-0.78=0怎么解?
∵x²+0.5x-0.78=(x+0.25)^2-0.8425=0∴(x+0.25)^2=0.8425,∴x≈0.9179-0.25=0.6679