Basically if you know your addition just add the values of each coin or dollar bill. Just forget about the $ sign or cent sign when adding the values together.
FOR EXAMPLE:
$1 and $2.75
You would ignore dollar sign and add together like normal to get
3.75
But remember to add dollar sign back at the end.
If the value only have 2 values with cents it should be something like
0.54 cents BUT NO DOLLAR SIGN
Hope that helps
Hmm, the slope is undefined. But like what exactly are you looking for as an answer?
Uhm, did you, maybe, type in the problem wrong? The answer to this equation is: 18/5 or 3.6, lol, no worries, though!
I'm pretty sure $39.31 was the original sales cost because if you use proportions to find out what is 7.2% of 42.35 ( what you get you you subtract 45 by 2.65). Your equation would be x/42.35 = 7.2/100. 42.35 is the whole because tax is adding money onto your original cost, making that the part. When you cross multiply you get 100x = 304.92. Then you divide by 100 on both sides to isolate the variable, to get x = 3.04. But you don't stop there. Since 3.04 is only the 7.2%, you have to subtract that by 42. 35 to get a sum of 39. 31 as your total.