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If    x+ 3y = 3     and    2x-y = -2

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seedrasoso | Student, Grade 10 | eNoter

Posted November 11, 2010 at 4:41 AM via web

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If    x+ 3y = 3     and    2x-y = -2

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hala718 | High School Teacher | (Level 1) Educator Emeritus

Posted November 11, 2010 at 4:48 AM (Answer #1)

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x+ 3y = 3...............(1)

2x - y = -2..............(2)

We have a system with 2 equations and 2 variable, then we will use the substitution method to solve:

First let us rewrite equation no. (2).

2x - y = -2

==> y= 2x + 2 ...............(3)

Now we will susbitute y value from (3) into eq. (1):

==> x+ 3y = 3

==> x+ 3(2x+2) = 2

==>  x+ 6x + 6 = 2

==> 7x + 6 = 2

==> 7x = -4

==> x = -4/7

Now subsittue x value in (3):

y= 2x + 2

y= 2(-4/7) + 2

  = -8/7 + 2

   = (-8+14)/7 = 6/7

==> y= 6/7

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