Answer:
There would be 5 triangles on the other side
Explanation:
If the right side has 1 circle and 1 square, that would mean that there is 5g+10g=15g weight on the right side
In total, there is 30g, and we already have 15
We can use the equation 15+3x=30, and by solving, the answer would be 5 triangles.
Hope this helps!