A toothbrush and toothpaste cost one dollar and ten cents total. The toothbrush costs a dollar more than the toothpaste. How much does the toothpaste cost?

Cost of the toothbrush and the toothpaste together = $1.10

Let us assume the cost of the toothpaste = x

Then

The cost of the toothbrush is = (x + 1) dollar

Then we can write the equation as

x + x + 1 = 1.10

2x + 1 = 1.10

2x = 1.10 - 1

2x = 0.10

x = 0.10/2

=.05 dollars

So the cost of the toothpaste is 0.05 dollars. I hope the procedure is clear to you.