(x+30)²/4+x²=(x+30)²
(x²+60x+900)/4+x²=x²+60x+900
(x²+60x+900)/4=60x+900
两边乘4
x²+60x+900=240x+3600
x²-180x=2700
x²-180x+8100=2700+8100
(x-90)²=10800
x-90=±60√3
x=90±60√3
对不起,刚才算错了
[(x+30)/2]²+x²=(x+30)²,求x,
(x+30)²/4+x²=(x+30)²
(x²+60x+900)/4+x²=x²+60x+900
(x²+60x+900)/4=60x+900
两边乘4
x²+60x+900=240x+3600
x²-180x=2700
x²-180x+8100=2700+8100
(x-90)²=10800
x-90=±60√3
x=90±60√3
对不起,刚才算错了