Answer:
Step-by-step explanation: add the equations
2x² = 30
x² = 15
y² = 12 - 15
= -3
x4 -y4 = 15² - (-3)²
= 216
Answer:
2.92 Rounded to the 100th
Step-by-step explanation:
If 6 of the 13 books are new, then 7 of them are used. The ratio of new (6) to used (7) is
6:7 or 6/7
Ratio of all books (13) to used books (7) is
13:7 or 13/7
Answer:
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Step-by-step explanation: sorry lol
Answer:
John is 17,
Susan is 14,
and Khalid is 9.
Step-by-step explanation:
a = John's age
b = Susan's age
c = Khalid's age
Let's set our rules from the given information.
a = b + 3
c = b - 5
a + b + c = 40
Now, we can solve for b through substitution.
(b + 3) + b + (b - 5) = 40
3b - 2 = 40
3b = 42
b = 14
So, now that we have Susan's age, we can follow the rules and see if it holds.
17 + 14 + 9 = 40 Viola!