Determine the simplified expression of the given equation: $6(x+7)+(x+3)$

Step 1 ：Distribute the 6 to both terms inside the first set of parentheses: \( 6(x+7) = 6x + 42 \)

Step 2 ：Combine like terms: \( 6x + 42 + (x+3) = 7x + 45 \)

Step 3 ：\( \boxed{7x+45} \)