9514 1404 393
Answer:
24
Step-by-step explanation:
Let d represent Donald's age now. Then Natali's age now is d+38. The age relationship 5 years ago was ...
(d+38) -5 = 3(d -5)
d +33 = 3d -15 . . . . . eliminate parentheses
48 = 2d . . . . . . . . . . . add 15-d
24 = d . . . . . . . . . . . . . divide by 2
Donald is 24 years old now.
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<em>Alternate solution</em>
You can also work this by considering that 5 years ago, Natalie's age was more than Donald's age by twice Donald's age then. Hence Donald was 38/2 = 19 at that time. Now, Donald is 19+5 = 24.
B
Explanation:
4x-3-(x+4)
4x-3-x-4
3x-7
Answer:
Step-by-step explanation:
Calculating the average speed during this time interval is the same as calculating how many km he traveled per hour.
![\frac{km}{hr}:\frac{250}{2.5}](https://tex.z-dn.net/?f=%5Cfrac%7Bkm%7D%7Bhr%7D%3A%5Cfrac%7B250%7D%7B2.5%7D)
This is also the same thing as the unit rate. Do that division and find that he traveled 100 km/hr.
Tip = 12% × bill
$28 = tip + bill
$28 = bill + 12% × bill
$28 = bill (1 + 12%)
bill = $28÷(1+12%) = $25