21 POINTS!

what is value of x?

Which expression is equivalent to the expression shown?

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%)

Order 1100000, 314000, 965000, 1890000, from least to greatest.