He has a total of $58.19.
1 day = $2.74
58.19/2.74
21.24
You can't have 21.2 days, so you need to round down to 21.
Jim can buy lunch for 21 days before he runs out of money on his account.
The square root of negative four is 2
It's a simultaneous equation:
Steps:
1.Number the equations..
a+b=77 -1
a-b=13 -2
2. Choose what variable you want to use. In this case I would use the "b". Since the signs in front of the "b's" are different, add the two equations together
a + b = 77
+ + +
a (-b) = 13
Which gives;
2a = 90
Then solve to find a:
2a=90
a= 90/2
a=45
3.Then plug the "a" value into any of the original equations to find the "b" value. I would use equation 1 since the all the variables are positive.
a + b = 77
(45) + b = 77
b=77-45
b=32
4.Solution
a=45
b=32
He paid ...
-- The cost of the lunches (100% = 1.00 of it)
-- 15% of the cost as a tip (15% = 0.15 of it)
-- 12% of the cost as sales tax (12% = 0.12 of it)
Total that he paid = (1.00 + 0.15 + 0.12) = 1.27 of $248.40
= $315.47 .
Trevor is one generous guy !