Answer:
Francisco is 17.
Explanation:
Francisco is the youngest. This means that his three siblings are all older than he is.
Let
x = Francisco's age
"Consecutive" means that the ages of the siblings are in a row, like stairsteps. He is the youngest and the others are +1, +1 , +1.
The ages are x and x+1, the next one x+2 and the oldest is x+3.
x+x+1+ x+2 + x+3=74
The question said the sum of their ages is 74. "Sum" means we add the ages.
x+x+1+x+2+x+3 = 74
Combine like terms.
4x + 6 = 74
Subtract 6.
4x + 68
Divide by 4.
x = 17
Francisco is 17.
Check:
Francisco is 17, so his brothers or sisters are 18, 19, and 20.
17 + 18+19+20 = 74
74 = 74 Check!