NEED HELP EASY MATH please

hi i need help on this i dont know how to set it up...

"your family went out for breakfast. the bill was $35.40 and you want to leave a 15% tip. what was the total bill including the tip?"

so to set it up do i do 35.40/15 = x/100? i dont understand please help!

35.40 x .15 = $5.31

15% tip = 0.15

if you want to find how much the tip is, just multiply (35.40) x (0.15)

but since you want to find the total bill including the tip, add on the bill to that, i.e. (35.40) x (1.15)

total bill will be= (35.40)+(15% of 35.40)
= 35.40+(15/100*35.40)
now use BODMAS i.e Bracket Off Divide Multiply Add Subtract
therefore, bill=35.40+5.31=40.71 is answer

10% of 35.40 = 3.54
5% = 3.54/2 = 1.77

15% = 5.31

35.40 + 5.31 = 40.71 $ ANSWER

OR 35.4 X 1.15 = 40.71 $

You do x/35.4 = 15/100. Solve for x by cross multiplying.