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Solve the system of linear equations by substitution.

Solve the system of linear equations by substitution.-example-1

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Required solution :

Here we have been provided with two equations,

  • 2x + 3y = 0 (Equation No 1)
  • 8x + 9y = 18 (Equation No 2)

In the first equation :

⇒ 2x = 0 - 3y

⇒ 2x = - 3y

⇒ x = - 3y / 2

In second equation :

Here we would be substituting the value of x which we got above. And the method which we are using is substitution.

⇒ 8 (-3y/2) + 9y = 18

⇒ (8 × -3y / 2) + 9y = 18

⇒ (-24y / 2) + 9y = 18

⇒ -24y + 18y / 2 = 18

⇒ -6y / 2 = 18

⇒ -3y = 18

⇒ -y = 18 / 3

⇒ -y = 6

⇒ y = -6

Therefore, value of y is -6..!!

Finding out value of x :

⇒ x = - 3y / 2

Now, here let us substitute the value of y which we got above as -6 here.

⇒ x = -3 (-6) / 2

⇒ x = -3 × -6 / 2

⇒ x = 18 / 2

⇒ x = 9

Therefore, value of x is 9..!!

User Rens Tillmann
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