PLEASE HELP: Iron intake for a female adult is 3 mg more than twice the amount for a newborn. The amount for an adult female is 15 mg. How much should an infant receive?

Question

anonymous · Answer

If the iron intake for a newborn should be x, and the iron intake of a female adult is 2x+3=15, then you can solve for x.

anonymous · Answer

Important that you read word for word.  The problem says a female adult is (=)   it never says a newborn is (=)  so the newborn gets x
newborn = x
female adults = 2x + 3

The adult female = 15 so   2x + 3 = 15
Then you solve:  And x will be the amount the newborn receives.

anonymous · Answer

<3 Thanks Everyone! My problem with these word problems is trying to figure out how to sort out the equation. Once i have it, its super easy to solve. If I get mixed up I stay stuck on it for hours! <3 i appreciate everyone's help! Thanks again!

anonymous · Answer

I find it helpful to define variables right away.  If there is a subject of a sentence, it gets a variable letter.  So in your Zebra problem, the Zebra's running speed gets a Z.  The Cheetah's sprinting speed gets a C.  And so on.

Next I look at the relationships that are described between these variables.  So the Cheetah's speed is three times the Zebra's speed minus 61.  We have variables now, so this translates into a formula.  C=3Z-61.  

Now I examine what is given, and substitute into my general formula.  If the given is the Cheetah's speed, then I'm solving for Z.  And so on.

Practice, practice!