<h3>Answer is -2</h3>
I hope it is helpful for you ....
Answer:
11 years old
Step-by-step explanation:
If four brothers have the average age 6, then the sum of their ages is

years.
Let x years be the age of sister. If four brothers and their sister have the average age 7, then

Multiply this equation by 5:

The sister is 11 years old.
This answer is pretty simple. you see (5,-8) and (20,y). well the 20 is 4 times the 5 on the x value so multiply the y value by 4 to get your answer which Y=-32 in the 2nd corrdenants.
Think about it, 64 band members split equally into 8 rows. Sounds like division, right? If we're going to split them into each row, that would be eight members for each of the eight rows.
So the answer is that 8 members was in each row.
4 2/5 x 10 = 4x 10 + 2/5 * 10
40 + 4 = 44
26 x 2 1/2 = 26 x 2 + 26 * 1/2
52 + 13 = 65