breakeven point is the point where costs equal revenues.
in this case
revenues = 100,000 * 2.10 = 210,000
And total costs are fixed costs + (variable costs * units)
So ... 87,000 + 100,000x
210,000 = 87,000 +100,000x
123,000=100,000x
x= 1.23 per unit variable costs