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Zorluk: KolaySystems of Linear Equations

Two linear equations are defined as follows:

3x+2y=123x + 2y = 12
x2y=4x - 2y = 4

If the ordered pair (x,y)(x, y) satisfies both equations, what is the value of xx?

Cevap: 4

Cevap

The value of xx is 4.
Adding the two equations 3x+2y=123x + 2y = 12 and x2y=4x - 2y = 4 eliminates the yy terms, resulting in 4x=164x = 16. Dividing both sides by 4 gives the value of xx as 4.

Adım Adım Çözüm

1
Add the two equations together to eliminate the yy variable.
4x=164x = 16
Since the coefficients of yy are opposites (22 and 2-2), adding the equations eliminates yy directly.
2
Divide both sides of the equation by 4.
x=4x = 4
To isolate the variable xx.

Anahtar Kavram

Solving systems of linear equations using the elimination method.

Alternatif Yöntem

We can solve the second equation for xx to get x=2y+4x = 2y + 4. Substituting this expression into the first equation gives 3(2y+4)+2y=123(2y + 4) + 2y = 12, which simplifies to 6y+12+2y=126y + 12 + 2y = 12, or 8y=08y = 0, meaning y=0y = 0. Substituting y=0y = 0 back into x=2y+4x = 2y + 4 yields x=4x = 4.
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