David W. answered • 04/23/19

I'll help you understand math!

Oooooh, these sorts of problems ised to give me fits!

4a + 3p = 0.9

3a + 4p = 0.85

This looks like a case for elimination! Which should we eliminate, a or p? It doesn't matter, but I'm gonna do a. The LCM of 4 and 3 is 12, so how can we get 12 and -12?

We can multiply the top by 3 and the bottom by -4, or -3 and 4. Again, either will work.

3(4a + 3p) = 3(0.9)

-4(3a + 4p) = -4(0.85)

12a + 9p = 2.7

-12a - 16p = -3.4

Now, if we add the two equations together, 12a + (-12a) = 0, so a cancels out!

-7p = -0.7

p = 0.1

Hey, one pear costs 10 cents.

4a + 3(0.1) = 0.9

4a + 0.3 = 0.9

4a = 0.6

a = 0.15

Aaaaand, one apple costs 15 cents.

Hope this helps!