The difference of two numbers, a and b, is 21. The difference of 5 times a and b two times b is 18

Draw two possible rectangles for each perimeter of 20 units

A car is purchased for 16,000. Each year it loses 20% of its value. After how many years will the car be worth 4,400 or less?

What is the length of the diagonal of a box with dimensions of 4x12x3

Two scientists are measuring lava temperatures. One scientist records a temperature of 1725°F. The other scientist records a temperature of 950°C. Which is the greater temperature? (Use C = 5 - 9 (F - 32).)

Tom sells cellphones for $45 a phone. Sam sells tablets for $149 a tablet but he is not making any profit yet because he still needs to pay off his order of $4992. when will the two guys make the same money? How much money will they both have?

How much is $3,204 plus $79,402?

Mario has b books. After receiving 5 new books for his birthday, he had 18 books

Danny's 7 friends contributed an equal amount of money to buy him a birthday present. The present cost $84. How much money did each friend contribute?

How much will a saver earn in 10 years on a $100 deposit that earns 5% compound interest (compound annually) ?

Distributive property: Example: 6 (2x - 3) = 12x - 18 "Combine like terms" means 3x + 4x = 7x. But we cannot add 3x + 4. Simplify, don't solve for x, just simplify, write it with only one x and no parenthesis: 2 (4x - 1) + 3x =