I'll treat these like they're two seperate problems because how you set it up they're not together. If it's one whole problem please tell me and I'll solve it that way. :-)
First one: 3x+9+8x + 12
Collect like terms and simplify
(3x+8x)+(9+12)
11x+21
Second one: 2x + 6+x² + 6x + 9
Collect like terms and simplify

8x+15+
Hope this helps you, have a BLESSED and wonderful day, as well as a safe one!
-Cutiepatutie ☺❀❤
Hj and jk are the same length line segments ( because the midpoint divides a line into two equal parts)
So hj = jk.
hk is the line segment which has the mid point j. It is the double of hj or jk. It can be the sum of hj and jk.
hj + jk = hk
or
2 * hj = hk
or
2 * jk = hk
S+d=209
d=209-s
6.5s+2d=836.5
6.5s+2(209-s)=836.5
6.5s+418-2s=836.5
4.5s+418=836.5
4.5s=418.5
s=93
There were 93 salads sold that day.
12÷3=4
cause 1/3 in this situation is 3 cause 12÷4 is 3