x^2-(x-4)^2=56
解:
要过程及答案!!!
x²-(x-4)²=56
x²-(x²-8x+16)=56
x²-x²+8x-16=56
8x=72
x=9
x²-(x²-8x-16)=56
x²-x²+8x=16=56
8x=40
x=5
“^” 这是什么意思?
8x-16=56