=-20(x^2-70x+1225-225)这个方程怎么算就解下=-20(x-35)^2+4500了?

问题描述:

=-20(x^2-70x+1225-225)这个方程怎么算就解下=-20(x-35)^2+4500了?
这是一道数学题.

=-20(x^2-70x+1225-225)
=-20(x^2-70x+1000)
=-20((x-35)^2-35^2+1000)
=-20((x-35)^2-225)
=-20(x-35)^2+4500