Respuesta :

Answer:

3x+15

Step-by-step explanation:

3(x+1)+12=3x+15

3x+3+12

Answer:

3x+3=12

Step-by-step explanation:

You do 3 times x which equals 3x and then you do 3 times 1 which is 3. so the problem is 3x+3=12, and then do 3-3, not 3x - 3. It's just 3-3, and then after that 12-3=9 9 divided by 3 is 3. x is the number that helps it go into that number

x=3.