Answer :
Answer :
[tex]\begin{gathered} 4d+9d-(7-6d)=4d+9d-7+6d \\ =4d+9d+6d-7 \\ =19d-7 \end{gathered}[/tex]Explanation :
From the given expression :
[tex]\begin{gathered} 4d+9d-(7-6d)=4d+9d-7-6d \\ =4d+9d-6d-7 \\ =7d-7 \end{gathered}[/tex]The error is in the first line in the parenthesis.
It should be like this :
[tex]-(7-6d)=-7+6d[/tex]The sign of 6d must be positive because if you will distribute the negative sign outside the parenthesis to the negative sign inside the parenthesis, negative x negative = positive.
Since the first line is not correct, the succeeding lines is also not correct.
The corrected solution will be :
[tex]\begin{gathered} 4d+9d-(7-6d)=4d+9d-7+6d \\ =4d+9d+6d-7 \\ =19d-7 \end{gathered}[/tex]