How do you write 0.40 as a fraction in simplest form

Jessica is a custodian at oracle arena.she waxes 20 m2 of the floor in 3/5 of an hour. jessica waxes the floor at a constant rate.at this rate how many sqaures meters can she wax per hour

The perimeter of a triangle is 69 cm. the first is 5 cm shorter than the second side. the third side is twice as long the first side. find the length of each side

In the diagram below de and ed are tangent to 0 which expression gives the measure of def