Answer :

Certainly! Let's simplify the expression step-by-step.

You have the expression:
[tex]\[ 9u + 4u - 5u - 2u + 4u \][/tex]

To simplify, we need to combine like terms. In this case, all terms involve [tex]\( u \)[/tex], so we will add and subtract the coefficients of [tex]\( u \)[/tex].

1. Identify the coefficients of [tex]\( u \)[/tex] in each term:
- The coefficient of [tex]\( u \)[/tex] in [tex]\( 9u \)[/tex] is [tex]\( 9 \)[/tex].
- The coefficient of [tex]\( u \)[/tex] in [tex]\( 4u \)[/tex] is [tex]\( 4 \)[/tex].
- The coefficient of [tex]\( u \)[/tex] in [tex]\( -5u \)[/tex] is [tex]\( -5 \)[/tex].
- The coefficient of [tex]\( u \)[/tex] in [tex]\( -2u \)[/tex] is [tex]\( -2 \)[/tex].
- The coefficient of [tex]\( u \)[/tex] in [tex]\( 4u \)[/tex] is [tex]\( 4 \)[/tex].

2. Add the coefficients together:
[tex]\[ 9 + 4 - 5 - 2 + 4 \][/tex]

3. Perform the arithmetic step-by-step:
[tex]\[ (9 + 4) = 13 \][/tex]
[tex]\[ (13 - 5) = 8 \][/tex]
[tex]\[ (8 - 2) = 6 \][/tex]
[tex]\[ (6 + 4) = 10 \][/tex]

So, the sum of the coefficients is [tex]\( 10 \)[/tex].

4. Multiply the sum of the coefficients by [tex]\( u \)[/tex]:
[tex]\[ 10u \][/tex]

Therefore, the simplified expression is:
[tex]\[ \boxed{10u} \][/tex]