2X^2+3X+1
X^3-2.5X
2*X^2+4
3X*X+X-1
XXX+2XX+3X+4
X^2+3X-5XX+5
X2X
2XY
2 / X
2X / Y
X^0.5
2X^2/X+5
X^0.5*X^0.5