Answer:
Step-by-step explanation:
a) Here we have:
"In Family A, the youngest child is 7 years younger than the oldest, who is 18"
Let's define:
Y = age of the youngest child.
O = age of the oldest child.
Then we know that:
Y = O - 7
O = 18
Then we can replace the second equation into the first one:
Y = 18 - 7 = 11.
b) Here we have:
"In Family B, the middle child is 5 years older than the youngest child."
Let's define:
Y = age of the youngest child.
M = age of the middle child.
Here we have only one equation:
M = Y + 5.
Answer:
(3x + 5)/2 = 7
Step-by-step explanation:
If you substitute 3 for x, you get the equation:
(3(3) + 5)/2 = 7
(9 + 5)/2 = 7
14/2 = 7
You divide 5 and 16 to get the answer: 0.3125.
