Currently reading - The complete idiots guide to algebra word problems.
I'm not good at math and I'm struggling to understand the inverse proportion formula(s). a1/a2 = b2/b1
Why does that work?
Proportional is intuitive to me.
Inversely proportional isn't.
I see the numbers are flipped I just don't understand why that works.
An example they give: 4 workers can finish a job in 6 hours. How long will it take 7 workers.
x is time it will take for 7 workers
4/7 = x/6
Cross multiply gives you 24=7x
x=3.42 hours
Let me back up one step.
Do you understand why you need to invert the second fraction when you are dividing two fractions?
I feel like these are contingent on each other. If you understand the first, you would understand the second.
In a very basic sense, since the answer goes down as the variable goes up (in both division and in inverse proportions), it needs to be inverted in order to produce that result. Why the answer is indeed accurate, I still need to think about more.