If an orange costs m cents, an apple costs m - 7 cents. We can't combine the two unless we are given a value for m.
7 oranges cost 7m cents, m + m + m... = 7 x m, but we just say 7m, like 7 of you would be 7 Chums.
One apple costs m - 7 cents. Two apples would cost 2(m - 7) = 2m - 14 cents, using the distributive property.
So, 7 oranges and an apple cost 7m + (m - 7). Again, using the distributive property, that's 7m + m - 7 cents.
Now, just like we don't call me 1 David, m is 1m, but since we only have one, we call it by its name.
m + 7m = 1m + 7m = 8m, like Chum + 7 Chums = 8 Chums.
Because we aren't given a value for m, the - 7 is still separate.
8m - 7 cents is what she paid for 7 oranges snd an apple.
Now, we are told that m = 50, so we put 50 where m is. Remembering that 8m means 8 x m...
8(50) - 7 = 400 - 7 = 393 cents = $3.93.
Let's check.
7 oranges is 7(50) = 350 cents
1 apple is 50 - 7 = 43 cents
350 + 43 = 393 cents = $3.93
Hey we got the right answer(the most important part of my pencil is the eraser!). Hope this helps!
