All of the following proportions are equivalent except
a/b=c/d
b/a=d/c
a/d=c/b
a/c=b/d

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

You are at a restaurant and owe $56.20 for your meal. you want to leave an 18% tip. approximately how much is your tip?

If you could answer these your a life saver