2r2 + 3s3 - r2 + 4t2 - r2 if r = - 2, s = - 3, and t = 5

W=3y-2n. Work out y if W=19 and N=7

5*+9y, when x=8 and y=11

Solve by elimination. 12.5x+8y+10z=1925 x+y+z=200 2y=x

Half of your baseball card collection got wet and was ruined. you bought 14 cards to replace some that were lost. how many did you begin with if you now have 40? A. 80 B. 52 C. 94 D. 66

What number is 32% of 200?

Sharita does special typing jobs for scientists. She charges $7 for 3 pages and $3 for each additional page of scientific typing. Sonia, a biologist, paid $97 to have a research paper typed

How many times can 2 go into 18

How many five-letter codes can be made if no letter can be used twice? (There are 26 letters in the alphabet.)

How to prove using basic definitions, If xy=xz then y=z

Some species of hummingbirds appear to hover in mid-air by flapping their tiny wings 85 times per second. How many times do their wings flap in one minute?