6:2(1+2)=

To solve the expression \( 6:2(1+2) \), we follow the order of operations, often remembered by the acronym PEMDAS (Parentheses, Exponents, Multiplication and Division from left to right, Addition and Subtraction from left to right).

1. First, solve the parentheses: \[ 1 + 2 = 3 \] Now the expression looks like this: \[ 6:2(3) \]

2. Next, handle the division and multiplication from left to right. The division \( 6:2 \) is the same as \( 6 \div 2 \): \[ 6 \div 2 = 3 \] Now the expression is: \[ 3(3) \]

3. Finally, multiply: \[ 3 \times 3 = 9 \]

Thus, the final answer is: \[ \boxed{9} \]