What is the best solution of the system of equations? y= 3x-4 -3y= -9x +12
a) no solution
b) (4,8)
c) infinitely many solutions
d) (2,-2)

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%)