Wilbur landed his plane

the elevation relative to the ground ( in meters) as a function of time (in seconds) is graphed

how long was the decent by 50 meters ?

A)100 seconds
B)10 seconds
C)250 seconds
D)50 seconds

Simplify the expression. -2/5(10+15m-20n)

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

Ireally need subtract and simplify.(-y^2 – 4y - 8) – (-4y^2 – 6y + 3)show your work, ! i will mark you brainliest but you have to show your work.