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Solve the system using substitution 0.1x+0.2y=1 y/5=x-3

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helga95 | eNoter

Posted September 10, 2011 at 11:31 PM via web

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Solve the system using substitution

0.1x+0.2y=1

y/5=x-3

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giorgiana1976 | College Teacher | Valedictorian

Posted September 10, 2011 at 11:37 PM (Answer #1)

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We'll manage the bottom equation of the system and we'll multiply by 5 both sides:

y = 5(x-3)

We'll remove the brackets:

y = 5x - 15

We'll substitute y within the top equation:

0.1x + 0.2(5x - 15) = 1

We'll remove the brackets:

0.1x + x - 3 = 1

We'll combine like terms:

1.1x - 3 = 1

We'll isolate x to the left side:

1.1x = 1 + 3

1.1x = 4

x = `4/1.1`

x = `40/11`

y = 5x - 15 => y = `200/11 ` - 15 => y = `-35/11`

The solution of the system of equations is represented by the pair (`40/11`  ; `-35/11` ).

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