Can you solve this question as soon as possible. , advance (its discrete math question )
1. prove the following about the empty set using both the elementwise and algebraic methods of proof:
(a) ∩ − = ∅
(b) ⊆ ℎ ∩ = ∅
(c) − ∩ ∩ = ∅

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40

i agree because i see the other persons thinking is clear

there still no table