To solve this, we first substitute the value of a + b = 7 into the expression:
3(28a + b) - 73a + 8b= 3(28(7-b) - 73(7-b) + 8b= 3(196 - 28b) - 511 + 73b + 8b= 588 - 84b - 511 + 73b + 8b= 77 - 4b
Therefore, the simplified expression is 77 - 4b.
To solve this, we first substitute the value of a + b = 7 into the expression:
3(28a + b) - 73a + 8b
= 3(28(7-b) - 73(7-b) + 8b
= 3(196 - 28b) - 511 + 73b + 8b
= 588 - 84b - 511 + 73b + 8b
= 77 - 4b
Therefore, the simplified expression is 77 - 4b.