Let assume
X for ice cream cones
Y for sundaes
X+Y=172
X=172-Y……..*
1.10X+2.35Y=294.20
Substitute * in the above equation
1.10(172-Y)+2.35Y=294.20
189.2-1.10Y+2.35Y=294.20
1.25Y=294.20-189.2
1.25Y=105 divide both sides by 1.25
Y=84
The substitute Y value in * equation
X=172-84
X=88
Therefore
88 ice cream cones and 84 sundaes were sold!!