Find a and b when `(a-2b,13)=(7,2a-3b).`

Find a and b , when (2a+b,11)=(1,a-3b).

If a/b=7/3 then find the value of (2a^2+3b^2)/(2a^2-3b^2) .

If a^(2) +b^(2) = 13 and ab= 6 find: 3(a+b) ^(2) - 2(a-b)^(2)

7.If a=3 & b=2 then find (a-b)^a

If the 7th and 8th term of the binomial expansion (2a - 3b)^(n) are equal, then (2a +3b)/(2a-3b) is equal to a) (13-n)/-(n+1) b) (n+1)/(13-n) c) (6-n)/(13-n) d) (n-1)/(13-n)

When the positive integer a, b, c and are divided by 13 the respective remainders are 9, 7 and 10. Find the remainder when a+2b+3c is divided by 13.

If (15a^2+4b^2)/(15a^2-4b^2) = 47/7 then find the value of the ratio : (7a-3b)/(7a+3b)