Answer:
23
Step-by-step explanation:
just trust me
So the pattern is x,y so the left is x and the right is y. Just graph it
Remember that there is 100 centimeters in a meter, and 1000 meters in a kilometer. If you multiply both values together (so you have a conversion of centimeters to kilometers) you get 100,000. Therefore, 100,000 centimeters makes a kilometer. Divide 320,000 by 100,000 and you get 3.2. Therefore, a centimeter would represent 3.2 kilometers.
1. Given (12+3)x, we can sum the numbers in the parenthesis to get 15x
2. Given 12x+3x, we can factor x to get (12+3)x and get the same as 1.
3. Given (12+3x)x, we have to distribute the x and we have 
4. This expression is already simplified.