Answer:
not sure sowy
Step-by-step explanation:
Let c and d be the number of cds and dvds respectively.
c+d=12
c=12-d
The we are told that:
2c+3d=31, using c found above in this equation gives you:
2(12-d)+3d=31
24-2d+3d=31
24+d=31
d=7
So Phillip bought 7 dvds.
check...
3*7+2(12-7)=31
21+2(5)=31
21+10=31
31=31
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!
Y = 4x - 1
// Plug this in for variable y in equation [1]
[1] 20x - 5•(4x-1) = 5
[1] 0 = 0 => Infinitely many solutions
