Simplify the following expressions :
`2/3 (3a+ 6b ) - 5a - 2/5 b `

Simplify the following expressions. (5^(2))^(3)

Simplify the following expressions : 2/3 (2a-b) +1/2 (a-2b+c) - 1/3 c

Simplify the following expressions : 1/2 (a - 3b) - 2/3 (1/4 a - 4/3b)

Simplify the following expressions : (i) (2/3+3/4) div (7/5-5/6) " (ii) "(2""1/3-1""1/2)" of " 3/5+1""2/5 div 2""1/3 .

Simplify the following algebraic expressions : a^(2) - [b^(2) - {a^(2)-(2b^(2)- bar(a^(2)+b^(2)) }]

Simplify the following : 3/7" of " 5""5/6

Find the sum of the following algebraic expressions : 3a - 4b + 5c , 2a + 3b - 6c , - 5a + 8b + 7c

Add the following algebraic expressions : 2a - 3b + 4c , -3a + 2b - 5c , 7a - c and 3b + 6c

Simplify the following expressions: (i) (3+sqrt(3))\ (3-sqrt(3)) (ii) (sqrt(5)-\ sqrt(2)\ )(sqrt(5)+sqrt(2))

Simplify the following expressions: (i) (3+sqrt(3))(2+sqrt(2)) (ii) (5+sqrt(7))(2+sqrt(5))