# Mark the correct alternative in each of the following:

Question:

Mark the correct alternative in each of the following:

If $x<7$, then

(a) $-x<-7$

(b) $-x \leq-7$

(c) $-x>-7$

(d) $-x \geq-7$

Solution:

$x<7$

subtracting $x$ on both sides, we get

$\Rightarrow x-x<7-x$

$\Rightarrow 0<7-x$

subtracting 7 on both sides, we get

$\Rightarrow 0-7<7-x-7$

$\Rightarrow-7<-x$

$\Rightarrow-x>-7$

Hence, the correct option is (c).