Answer:
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:
2. Tom ran from his house to the bus stop and waited. He realised that he missed the bus so he walked home
Step-by-step explanation:
He ran to the bus stop so his distance from his home is far, then he waited so the distance did not change, and then he went back home so the distance to the house got smaller again.
5.9 × 10^24 = 5,900,000,000,000,000,000,000,000 minus
13,000,000,000,000,000,000,000 equals
5,887,000,000,000,000,000,000,000 kg
which is the amount greater that Earth's mass is. you could write this problem as
5.9 × 10^24 - 13 × 10^21 = 5.887 × 10^21
