I Answer
The retail price is 60$.
Step-by-step explanation:
Ok, for this question, we need to be able to find out what is 100 percent if 70 percent is 42. The first step you should take is to make a proportion.
The two fractions you should have is 42 over x, and 70 over 100. These two fractions represent that 42 is equal to 70 out of 100 and the x represents the value that we do not know.
First, cross multiply 42 and 100. That equals 4200. Then cross multiply 70 and x. This is an optional step as you can just divide. (You will see what I mean later). So if you cross multiply 70 and x, you will get 70x. Now we have an algebraic equation. Our equation is 70x = 4200. To solve an algebraic equation we need to isolate the variable, x.
To Isolate it, we need to divide the 70 that is attached to the x, symbolizing multiplication. This is called the coefficient (No offense if you know that already). Once you divide 70x by 70, x is now by itself, you then need to divide 4,200 by 70 which gives you 60. (Note that whenever you do something to one side of an algebraic expression you need to the do the same to the other side.) Our final equation is now x = 60 which represents 100 percent, or the original price.
(You don't have to do the whole algebra thing. Just divide whatever you have that is not part of the first cross multiplication. If you are confused what to cross multiply first, just remember not to cross multiply the variable.)
Hope this helped :)
