Verify that parallelogram ABCD with vertices A (-5,-1), B (-9,6), C (-1,5) and D (3,-2) is a rhombus by showing that it is a parallelogram with perpendicular diagonals.

The altitude of a plane as it begins to descend is shown by the linear equation a = 30,000 - 1500m, where a is the plane's altitude, in feet, and m is minutes. What is the plane's altitude when m = 12?

Solve the system using substitution. y = - 6x+54 5y-x+9=0

Write 7/10 as a sum of fraction two different ways

Is 100 students for every 2 buses unit rate?

Three times a number minus 9 is equal to two times the number plus 7

Tabitha's hiking distance in july was 2/5 miles she wrote the distance of 2.02 miles what error did she make?

Solve Y/5.6 = 12 for y

How to reduce 3/63 to its simplest form

Find the next three term sequence 2,8,32,128

Given that x and y are real numbers, find the value of x and y if (x+y) + (x-y) i=7+3i