Hey there!
"The sum of two numbers is 48..." means that the two numbers will be added together and will equal 48.
"...the larger number is 6 less than twice the smaller number..." means that if the smaller number is represented by x, the larger number will be 2x – 6, or twice the smaller number minus 6.
The final equation will be (2x – 6) + x = 48. Now, all you need to do is simplify.
(2x – 6) + x = 48
1(2x – 6) + 1x = 48
2x + 1x – 6 = 48
3x – 6 = 48
+ 6 + 6
3x = 54
3 3
x = 18
So, the smaller number (x) will be be equal to 18 and the larger number (2x – 6) will be equal to (2)(18) – 6, or 30. You can check this by adding these numbers together:
18 + 30 = 48
Hope this helped you out! :-)