5x - 2y + 1z = 8 ⇒ 5x - 2y + 1z = 8
-9x + 2y + 2z = 5 ⇒ -9x + 2y + 2z = 5
-9x - 2y - 5z = 4 -4x + 3z = 13
5x - 2y + 1z = 8
-9x + 2y + 2z = 5 ⇒ -9x + 2y + 2z = 5
-9z - 2y - 5z = 4 ⇒ -9x - 2y - 5z = 4
-18x - 3z = 9
-4x + 3z = 13
-18x - 3z = 9
-22x = 22
-22 -22
x = -1
-18x - 3z = 9
-18(-1) - 3z = 9
18 - 3z = 9
- 18 - 18
-3z = -9
-3 -3
z = 3
5x - 2y + z = 8
5(-1) - 2y + 3 = 8
-5 - 2y + 3 = 8
-2y - 5 + 3 = 8
-2y - 2 = 8
+ 2 + 2
-2y = 10
-2 -2
y = -5
(x, y, z) = (-1, -5, 3)
The answer is 7 3/4 inches.
I noticed the word "train" in the problem and I knew I had to help you! :)
Answer:
3a. 8t + 12c = 72
3b. t + c = 7
Step-by-step explanation:
number of tapes is t
number of Cds is c
so 8t + 12c = 72
and t + c = 7
so t = 7 - c
replace t = 7 - c in to the first equation
8(7 - c) + 12c = 72
56 - 8c + 12c = 72
4c = 72 - 56 = 16
c = 4
if c = 4, then t = 7 - c = 7 - 4 = 3
