A2X+1+C2X−1=23⇔2X(X+1)+(X-2)(X-1)=46 1,5⇔X=4⇔X=4

câu 3:

A

2

x

+

1

+

C

2

x

1

=

23

2x(x+1)+(x-2)(x-1)=46

1,5

x=4