Suppose I have two inequalities: $$k_1 \leq a$$ $$k_2 \leq b$$
where $k_1,k_2,a,b$ are all positive numbers
I know that that summation of them can be written as: $$k_1+k_2 \leq a+b$$
But I want to find $$k_1-k_2 \leq ?$$ or $$? \leq k_1-k_2$$
Is there any way to solve this problem?