Algebra Warm up:

7.6 Classic Puzzles in Two Variables pg. 353 to 359

What are they talking about?

These types of problems involve 2 missing items that you can solve for by making a system of equations!

(remember the video about the band aids and rubber bands?)

THESE are ALL word problems!

Remember to read carefully.Write down important informationYOU WILL have two variables--it helps to identify them first!Label your unknowns.Most of these will best be solved by elimination!Remember--two situations that are related!

YOU must come up with 2 equations to proceed!!!!

AGE PUZZLES

They key is how to represent a person's age in the past or the future.

pg. 354

Try another....

WIND AND CURRENT PUZZLES

The trick here is common sense! When an object travels "with" something you are ADDING that on!When an object travels "against" something you are SUBTRACTING it!

Think d=rt!!!!!

NUMBER DIGIT PUZZLES

The trick is to write the number in expanded form.

pg.355

COIN PUZZLESOne equation involves what you physically have!One equation involves the monetary value!

pg.356

Try another.....

CHEMICAL-SOLUTION PUZZLESInvolve mixing of chemicals in percent solutionsTrick here is to remember to change the % to decimals and to keep track of the ounzes or grams.

pg. 356

Try another...

That was ALOT to deal with.....That is why we are doing this section separately!Quiz is Monday!!!!

Keep in mind the best ways to solve various puzzles!

Remember you have 2 variables! Define them first!You need 2 equations! Try using a table.

(like things together)Solve like a system of equations!The HARD part is coming up with the equation so we practice it!

Now you all try some pg. 358 # 5-9JUST come up witht he equations!!!DO NOT SOLVE.