PLEASE HELP ME FIRST CORRECT ANSWER GETS THE CROWN

Find the value of x for which line a is parallel to line b

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%)

If bradley saves for 4 weeks, what is the total amount of money he will have saved?