Do the dioagonals of parallelograms intersect at right angles always, sometimes or never? Justify your reasoning.

A rectangle has a length of 3.6in and perimeter of 16.8 inches. What is the width of the rectangle?

What are irrational and rational numbers

How much less than 5x2 - 3x + 2 is 2x² + 5?

Round 514,733 to the nearest thousand

Melinda purchased 3 blank cassette tapes and 5 blank videotapes for a total of $22.10 not including tax. if each videotape cost twice the price of cassette tape, what did Melinda pay for 1 videotape?

Which of the following is a perfect square? 65, 144, 68, 131

How many times larger than 2 x 10 to the power of 3 is 6 x 10 to the power of 6?

Expand than simplify: 4 (7x+2y) + 8 (3x+5y)

The 6:00 am temperature for four consecutive days in the town of lincoln were - 12.1, - 7.8, - 14.3, and - 7.2. what was the average temperature for the four days

Express the exact solution to each equation as a base 20 logarithm. 21^x=30