10. the equation t 0.07c represents the tax, t, based on the cost, c, of an item. which part of the equation represents the constant of proportionality? ot 0.07

The constant of proportionality stays the same no matter what values the variables take, so in our example independently of the cost of the item (and of the tax value, which is dependent on the cost value).

Here the only value that does not change is the 0.007, the rate! - this is the correct answer.

This question doesn’t make any sense