The sum of two numbers is at least 8, and the sum of one of the numbers and 3 times the second number is no more than 15.

x≥4.5 y≤3.5

Step-by-step explanation:

let the first number be x

and the second number be y

the sum of the 2 numbers is at least 8

for at least we make use of these symbol ≥

x+y≥8

the sum of the first and 3 times the second is not more than 15

for no more than we make use of these symbol ≤

x+3y≤15

from equation 1 x≥ 8-y

put x≥8-y in equation 2

x+3y≤15

8-y+3y≤15

8+2y≤ 15

2y≤15-8≤7

y≤ 7/2 ≤ 3.5

y≤3.5

equate y≤3.5 back in x≥8-y

x≥8-3.5 ≥4.5