Answer:
Alex = 19 years
Bart's = 15 years
Carl = 8 years
Step-by-step explanation:
Let us represent their ages as
Alex = x
Bart's = y
Carl = z
the sum of the ages of the three brothers is 42
x + y + z = 42
Alex his age is three more than twice Carl's age
x = 2z + 3
The difference between Barts in Carl's ages is seven years
y - z = 7
y = 7 + z
Hence: we Substitute
x + y + z = 42
2z + 3 + 7 + z + z = 42
Collect like terms
2z + z + z + 10 = 42
4z = 42 - 10
4z = 32
z = 32/4
z = 8 years
Hence, Carl = 8 years old
a) y = 7 + z
y = 7 + 8
y = 15 years.
Hence, Bart's is 15 years old
b)x = 2z + 3
x = 2(8) + 3
= 16 + 3
= 19 years
Therefore, Alex is 19 years old.
