SALE PRICE: a department store is having a storewide twenty percent discount sale. the sale price S of an item that has a regular price of R is S=R-0.2R write the inverse equation. what is the regular price for an item that is on sale for $38.40??????????

Question

SALE PRICE: a department store is having a storewide twenty percent discount sale. the sale price S of an item that has a regular price of R is S=R-0.2R    write the inverse equation. what is the regular price for an item that is on sale for $38.40??????????

kropot72 · Answer

S = R - 0.2R
Can you simplify the right hand side?

anonymous · Answer

I'm confuzzled :/

kropot72 · Answer

What do you get when you subtract 0.2R from R?
R - 0.2R = ?

kropot72 · Answer

@jerr1996 Are you there?

anonymous · Answer

sorry computer problems :/
wouldn't that leave you .2?

kropot72 · Answer

No. Just to review the principle involved what do you get when you subtract R from 10R?
10R - R = ?

anonymous · Answer

9R?

kropot72 · Answer

Correct! So can you try this one again:
R - 0.2R = ?

anonymous · Answer

.8r?

kropot72 · Answer

Good work! So now the original equation is changed as follows:
S = R - 0.2R = 0.8R
S = 0.8R ...............(1)
Now we need to find the regular price R in terms of the sale price S. To do this you divide both sides of equation (1) by 0.8. Can you try that?

anonymous · Answer

would dividing it make it a fraction?

kropot72 · Answer

Yes, you get a fraction on the left hand side but not on the right hand side.

anonymous · Answer

so would it be S/.8=R?

kropot72 · Answer

Good work again :)
So now you have arrived at the 'inverse equation' and can calculate the regular price R by dividing the sale price (S = $38.40) by 0.8.

anonymous · Answer

48?

kropot72 · Answer

R = $48.00 is correct.

anonymous · Answer

Ahhhh!!!! :D Thank You!!! :D

kropot72 · Answer

You're welcome :)