find two integers such that their mean is 15 and 2 less the larger number is thrice the smaller number.​

Step-by-step explanation:

So we first need to assign letters to represent the numbers.

Let 'a' be the larger number and 'b' the smaller.

Now we can use this to write equations that we can solve simultaneously to find both 'a' and 'b'.

according to the question:

(a + b) ÷ 2  = 15   [1]

a = 3b              [2]

We can substitute 'a' in [2] for 'a' in [1]

⇒ (3b + b) ÷ 2  = 15

⇒    4b ÷ 2 = 15

⇒            b  = ¹⁵/₂

We can plug this value of b into equation [2] to solve for a

⇒  a = 3 (¹⁵/₂)

⇒  a = ⁴⁵/₂

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