Respuesta :

Answer:

-3

Step-by-step explanation:

First let's solve for u...

-3u+9=6

Subtract 9 from both sides...

-3u=-3

Divide both sides by -3

u=1

Now we plug 1 in for u in the expression 4u-7 to get...

4u-7=4(1)-7=4-7=-3