Which algebraic expression is equivalent to this expression 6(3x+5)-20

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%)

Select the correct answer and solve for y

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