Question

已知5X的平方减3X减5等于零,求5X的平方减2X减5X的平方减2X减5分之一等于几

Answer 1

5x²-3x-5=0

则5x²-2x=x+5

5x²-5=3x

x²-1=3x/5

所以5x²-2x-1/(5x²-2x-5)

=x+5-1/(3x-2x)

=(x²+5x-1)/x

=(3x/5+5x)/x

=3/5+5

=28/5