Answer:
b. (2, 5, 3)
Step-by-step explanation:
Trying the offered choices seems the fastest way to find the answer. The second choice works in all equations, hence is the solution.
Another strategy you can use is to see if the equations are dependent. Here, it looks like adding twice the third equation to the other two eliminates at least the x- and y-variables. If that eliminates z, then there are infinite solutions. Instead, it gives the equation ...
7z = 21
z = 3 . . . . . divide by 7
This answer is consistent with choice B, confirming that answer and eliminating the other choices.
1. Let x = #
2. "Five less than six times a number" can be written as: 6x - 5
3. "is at least" is the same as "greater than or equal to" and can be written as: >=
4. "nine subtracted from two times that number" can be written as: 2x - 9
5. the equation is: 6x - 5 >= 2x - 9
6. solve for x by grouping the x variable terms on one side and the constants on the other side:
6x - 5 >= 2x - 9
-2x +5 -2X +5
4x >= -4
7. divide each side by 4, and you get: x = -1
