Answer:
It appears to be substitution
Step-by-step explanation:
I think you are talking about system of equations
Answer:
4.4 cm
Step-by-step explanation:
To solve this problem, we have to remind the conversion factor between feet and cm. We know that:
1 foot = 12 inches
1 inches = 2.54 cm
So,

In this problem, Sarah's height right now is
h = 148 cm
She wants to be 5 feet tall by her next birthday: it means that her height should be

Therefore, she needs to grow by:

So, she needs to grow 4.4 cm more in order to be 5 feet tall.
I believe the answer is 5. Hope this was right for you.
If the remaining 4 letters can be anything, you have 2*26^4 = 913,952 possible 5-letter ham radio call signs.