Inequalities: Simultaneous Inequalities
If $$7 \le x \le 34$$ and $$12 \le y \le 42$$, which of the following inequalities gives all possible values of $$x-y$$?
Incorrect.
[[snippet]]
Incorrect.
[[snippet]]
Incorrect.
[[snippet]]
Read the question carefully. This is the range of $$x+y$$.
Incorrect.
[[snippet]]
This is a trap option. Subtract the maximum $$y$$ from the minimum $$x$$ to get the minimum value of $$x-y$$. Likewise, subtract the minimum $$y$$ from the maximum $$x$$ to get the maximum value of $$x-y$$.
Correct.
[[snippet]]
Subtract the maximum $$y$$ (42) from the minimum $$x$$ (7) to get the minimum value of $$x-y$$:
>$$\text{Minimum} = 7 - 42 = -35$$
Likewise, subtract minimum $$y$$ (12) from maximum $$x$$ (34) to get the maximum value of $$x-y$$:
>$$\text{Maximum} = 34 - 12 = 22$$
Hence, the minimum and maximum values of $$x-y$$ are -35 and 22, respectively.
$$-35 \le x-y \le 22$$
$$-13 \le x-y \le 76$$
$$5 \le x-y \le 18$$
$$19 \le x-y \le 76$$
$$46 \le x-y \le 49$$