the sum of the heights of three brothers is 221 inches. A is 8 inches taller than B and 5 inches taller than C. WHat is A's height in inches?
Substituting into b = a - 8 and c = a - 5 is probably more helpful...
I don't think you are done with your answer, so I'll just finish it for you.
We have the equation a+b+c=221, and we understand that \(b = a-8\) and \(c= a-5\). Substituting b and c with their values in terms of a, we have \(a + a - 8 + a - 5 = 221, \), which simplifies into \(3a = 234\). Dividing both sides by 3, we have \(a = 78\) , so a's height is \(\boxed{78}\) inches.
If you wanted to know the height of b and c, we can revisit the equations b = a - 8 and c = a - 5. Simplifying b = 78 - 8, we know that b is 70 inches tall, and simplifying c = 78 - 5, we know that c is 73 inches tall.
If you want to check your work, we can add 78, 70, and 73 to get 221, so our answers are correct.
Hope this helps,
- PM