Why is 2 to the power of -1 equal to 0.5 or 1/2

What are the sotions to the quadratic equation 9x^2=4

Divide the following fractions 3/4 ÷ 2/3 1/2 8/9 9/8 2

Solve the problem. a student earned grades of c, a, b, and a in four different courses. those courses had these corresponding numbers of credit hours: 4, 5, 1, and 5. the grading system assigns quality points to letter grades as follows: a = 4, b = 3, c = 2, d = 1, and f = 0. compute the grade point average (gpa) and round the result to two decimal places. 3.40 3.50 8.75 2.18