1. solve the system by elimination. 2.solve the system by substitution.

Step One

Add the first and third

-2x + 2y + 3z = 0

2x + 3y + 3z = 5

        5y + 6z = 5

Step Two

Add the second and third together.

- 2x - y + z = -3

2x + 3y + 3z = 5

       2y + 4z = 2            Divide this result by 2

         y + 2z = 1             multiply this result by 5

        5y + 10z = 5

Step three

Subtract the result of step 2 from the result of step one

         5y + 10z = 5

         5y +  6z = 5        Subtract

                  4z = 0

                    z = 0

Step Four

Solve for y

5y + 6z = 5     But z = 0

5y = 5

y = 1

Step Four

Solve for x . Use equation 3 in the givens.

2x + 3y + 3z = 5

2x + 3*1) + 3*0 = 5

2x = 5 - 3

2x = 2

x = 1

Answer

x = 1

y = 1

z =0       This has been checked and found to be correct.

Problem 2

Substitution is not the best way to do this. Divide the last equation by 2 and add it to the first one.

Step One

divide equation 3 by 2.

x + z = 2

Step Two

Add step one to equation 1

-x - y - z = - 8

x    +    z =  2

    - y = - 6

      y =   6

Step Three

Put this result into equation 1.

-x - 6 - z = - 8

-x - z = - 2

x + z = 2     Multiply this equation by 4

4x + 4z = 8

Step four

Put y = 7 into the second equation.

-4x + 4y + 5z =  7

-4x + 4*6 + 5z = 7

-4x + 24 + 5z = 7

-4x          +5z = -17

Step 5

Add the results from Step 3 and Step 4 together.

-4x + 5z = - 17

4x + 4z = 8

9z = - 9

z = - 1

Step 6

Find x

-x - y - z = - 8

-x -6 + 1 =- 8

-x - 5 = - 8

-x = - 3

x = 3      

Answers

x = 3

y = 6

z = -1    verified to be correct.

5   1/4   miles per hour

step-by-step explanation:

15   3/4 / 3 = 5   1/4

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 : )