一元二次方程4(5x-3)²-9(x-5)²=0的根为
问题描述:
一元二次方程4(5x-3)²-9(x-5)²=0的根为
答
4(5x-3)²=9(x-5)²
4/9=(x-5)²/(5x-3)²
2/3=(x-5)/(5x-3)
x=21/13、和x= - 9/7
答
4(5x-3)²-9(x-5)²=0
[2(5x-3)+3(x-5)][2(5x-3)-3(x-5)]=0
[10x-6+3x-15][10x-6-3x+15]=0
[13x-21][7x+9]=0
解得x=21/13、和x= - 9/7