In scientific opinion polling, a random sample is used to avoid:

A store sells rwo different types of coffee. Coffee a costs $7 per pound and coffee b costs $5 per pound. Amy bought 7 pounds of coffee and spent a total of $41. How many pounds of each type of coffee did she buy?

Three times a number + 12-5 times the same number is 22. What is the number?

The shortest side of a triangle measures 15 inches less than the longest side. If the third side is 2 inches shorter than the longest side and the perimeter is 103 inches, find the measure of the 3 sides.

Find the expression 5x + 10y-20

Alex ran 12.8 km in the morning. After lunch, he continued running. When he finished the run, he had covered 31.4 km in all. Write an equation that can be used to find how far Alex ran after lunch.

Grace and Max worked together on a math problem. they had a rectangle piece of paper that 14 inches long and 11 inches wide they where asked to cut this piece of paper into 1/8 inches wide strips using the length of paper how many 1/8 inches wide

If s (x) = 2 - x2 and t (x) = 3x, which value is equivalent to (s. t) (-7)

Kevin and his sister, katy, are trying to solve the system of equations. Keven thinks the new equation should be 3 (6x-1) + 2y=43, while katy thinks it should be 3x+2 (6x-1) = 43. Who is correct and why

If 4x=32 find the value of 35-5x

On Saturday, a local hamburger shop sold a combined total of 520 hamburgers and cheeseburgers. The number of cheeseburgers sold was three times the number of hamburgers sold. How many hamburgers were sold on Saturday