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yulyashka [42]
3 years ago
7

Solve the system by substitution

Mathematics
2 answers:
IceJOKER [234]3 years ago
6 0

1.

Answer:

<em>In Point Form:</em> (x,y,z)= (3,6,-1)

<em>In Equation Form:</em> x=3, y=6, z=-1

Step-by-step explanation:

<em> 1) Solve for x </em>

          2x+2z=4 (Subtract 2z from both sides)

          -2z  -2z

          2x= 4-2z  (Divide 2 from both sides)

          /2      /2

           x=2-z

<em>2) Substitute 2-z for x in </em>

                      -x-y-z=-8

                      -(2-z)-y-z=-8

                      -2+z-y-z=-8  (Combine Like Terms)

                      -2-y=-8 (Add 2 to both sides)

                      +2     +2

                      -y=-6  (Divide -1 from both sides)

                      /-1   /-1

                      y=6

<em>3) Substitute 2-z for x & 6 for y in </em>

                         -4x+4y+5z+=7

                         -4(2-z)+4(6)+5z=7  (Get rid of parentheses)

                         -8+4z+24+5z=7   (Combine Like Terms)

                         9z+16=7  (Subtract 16 from both sides)

                              -16  -16

                         9z+=-9  (Divide 9 from both sides)

                         /9     /9

                         z=-1

<em>4) Now find x by substituting -1 for z in  </em>

                                         x=2-z

                                         x=2-(-1)  

                                          x=2+1

                                         x=3  

<em>Therefore the answer is: </em>

<em>In Point Form:</em> (x,y,z)= (3,6,-1)

<em>In Equation Form:</em> x=3, y=6, z=-1

2. Answers:

<em>In Point Form:</em> (x,y,z)= (1,1,0)

<em>In Equation Form:</em> x=1, y=1, z=0

Step-by-step explanation:

                               -2x + 2y + 3z = 0             (1)

                               -2x - y + z = -3                  (2)

                                2x + 3y + 3z = 5              (3)

<em>Solve (1) and (2)  </em>

<em>Multiply 2 by 2</em>

                                -2x + 2y + 3z = 0

                                -4x -2y   + 2z = -6

                               -6x          + 5 z = -6        (4)

<em>Solve (2) and (3)</em>

<em>Multiply 2 by 3</em>

                              -6x - 3y + 3z = -9

                               2x + 3y + 3z = 5

                              -4x         + 6z = -4           (5)

<em></em>

<em>Solve (4) and (5)</em>

<em>Multiply (4) by 2 and (5) by -3</em>

                          -12x    + 10 z = -12

                           12x    -  18z   = 12

                                        -6z = 0

                                         z = 0

<em>Then</em>

           -4x + 6(0) = -4

          -4x = -4

           x = -4/-4

           x = 1

<em>Finally</em>

                -2(1) - y + (0) = -3      

               -2 - y = -3

                -y = -3 + 2

                y = 1  

<em>Therefore the answer is: </em>

<em>In Point Form:</em> (x,y,z)= (1,1,0)

<em>In Equation Form:</em> x=1, y=1, z=0

Andru [333]3 years ago
4 0
A solution on the photos

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