This is the hardest question I've answered all day.
One way to find a sub-total is by *simply* adding everything together, and a example would be below, buy yeah, you just add everything together.
For example:
Cookies (item # 594993) $2.98
Cake (item # 4354533) $4.50
Vans low tops (item # 594939) $60.00
Vans socks (item # 598993) $15.00
And just by adding all this, that how you would find the subtotal. Hope this helps! ;)
A suitable calculator shows the score of
46.0 separates the bottom 26% from the top 74%.

Substitute x = 3 in any given equations. I will do in y = - x + 1

Therefore the answer is (3,-2)
total bill before any discounts $13.
she is a student, so she gets 20% off.
she brought an item of clothing, so she gets 5% off.
so she's really getting 20% + 5% off, namely 25% off her bill.
