I need help ASAP. All you need is down below.

Write the fraction or mixed number and the decimal shown by the model

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)

What is the perimeter of an equilateral triangle if each side is (x+3)?