Write a system of equations to describe the situation below, solve using elimination, and fill in the blanks.
1 answer:
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30% of number A means
similarly, 40% of number B means
These must be equal, so we have
Multiply both sides by 10 to get
So, you can choose any number for A, and then you multiply it by 4/3 to get B. There are infinitely many solutions to this equation.
Answer:
B.
Step-by-step explanation:
To simplify something that looks like you would multiply the top and bottom by the conjugate of the bottom. So you multiply the top and bottom for this problem I just made by:
.
If you had , then you would multiply top and bottom the conjugate of
which is
.
The conjugate of a+b is a-b.
These have a term for it because when you multiply them something special happens. The middle terms cancel so you only have to really multiply the first terms and the last terms.
Let's see:
(a+b)(a-b)
I'm going to use foil:
First: a(a)=a^2
Outer: a(-b)=-ab
Inner: b(a)=ab
Last: b(-b)=-b^2
--------------------------Adding.
a^2-b^2
See -ab+ab canceled so all you had to do was the "first" and "last" of foil.
This would get rid of square roots if a and b had them because they are being squared.
Anyways the conjugate of is
.
This is the thing we are multiplying and top and bottom.