When I

When I am as old as my older brother is today, my brother will be twice as old as I am today.
a) How old is my brother if I am 8 years old today?
b) How old am I if my brother is 21 today?

Correct answer:

b =  12
k =  14

Step-by-step explanation:


j=8
j+x=b
b+x = 2•j

j = 8
b-j-x = 0
b-2j+x = 0

b = 12
j = 8
x = 4

Our linear equations calculator calculates it.

c=21
k+z=c
c+z = 2•k

c = 21
c-k-z = 0
c-2k+z = 0

c = 21
k = 14
z = 7

Our linear equations calculator calculates it.



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