二元二元一次解方程:(1)3x²-1=0 (2)x(2x+3)=5(2x+3)(3)x²-4x-2=0 (4)2x²-5x+1=0
问题描述:
二元二元一次解方程:(1)3x²-1=0 (2)x(2x+3)=5(2x+3)(3)x²-4x-2=0 (4)2x²-5x+1=0
答
(1)3x²-1=0 x^2=1/3x=±根号1/3(2)x(2x+3)=5(2x+3)2x^2+3x-10x-15=02x^2-7x-15=0(x-5)(2x+3)=0(x-5)=0x=5(2x+3)=0x=-3/2(3)x²-4x-2=0x²-4x+4=6(x-2)^2=6x-2=±根号6x=2±根号6(4)2x²-5x...