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2 years ago

I need help! I will give brainliest, if correct!

Mathematics

2 answers:

nekit [7.7K]2 years ago

5 0

kx + z = 3 means z = 3 - kx. Substitute this into the first two equations:

x + y + 3 (3 - kx) = 10 ==> (1 - 3k) x + y = 1

-4x + 3y + 5 (3 - kx) = 7 ==> (-4 - 5k) x + 3y = -8

Multiply through the first equation by -3 :

-3 ((1 - 3k) x + y) = -3 (1) ==> (-3 + 9k) x - 3y = -3

Add this to the second equation to eliminate y :

((-3 + 9k) x - 3y) + ((-4 - 5k) x + 3y) = -3 + (-8)

(-7 + 4k) x = -11

Normally, you would solve for x by dividing both sides by -7 + 4k. But you can't do that if this turns out to be equal to 0, which happens for

-7 + 4k = 0 ==> k = 7/4

ki77a [65]2 years ago

3 0

Answer:

k = 7/4

Step-by-step explanation:

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