K+a=500
how do i get k alone on one side of the equation ?

k = 500 - a

Step-by-step explanation:

As we need "k" alone in one side of eqn. , we need to substract "a" on both the sides of the eqn. so that we can cancel "a" which on the left side.

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