What is the answer to 3x-9=21

x=10

Step-by-step explanation:

Any number next to x like 3x you multiply so you take numbers 1-9 and put it as X  and work through every number and see which number makes the equation true.

3x-9=21

Move -9 to the other side. Sign changes from -9 to +9

3x-9+9=21+9

3x=30

divide by 3 for both sides

3x/3=30/3

Cross out 3 and 3, divide by 3 and then becomes 1*1*x=x

x=10

x=10

step-by-step explanation:

if you want to solve percent error follow these steps.

1. subtract the accepted value from the experimental value.

2. take the absolute value of step 1.

3. divide that answer by the accepted value.

4. multiply that answer by 100 and add the % symbol to express the answer as a percentage.

if you want to solve percent of change just do this.

1. work out the difference (increase) between the two numbers you are comparing.

2. divide the increase by the original number and multiply the answer by 100. if your answer is a negative number then this is a percentage decrease.

hope this : )