Solving systems equations by elimination

1 answer:

3 0

I won't answer them all for you (don't want to cheat - need to learn something).
But for the first one given:

<span>-2x-9y=-25
-4x-9y=-23

you set up either x or y (which ever one you want to eliminate) so that one of them cancels.
So this one is easy - you just have to multiply an entire row by negative (doesn't matter which one) - so that the y's will be + and -

Since they're both 9 and they're subracting NOW - you can eliminate the y value. Now add/subtract the x's. So it'd be -2 or 2 depending on how you eliminated y. Then add the number outside of the = sign. Now just solve for x. After that plug in whatever you got for x into both of the rows. Then find the y value.

Hopefully this wasn't confusing -- reply if it is and I will try to simplify. I can give you contact if you need help with the rest

Good luck!</span>

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If set A has 4 elements and B has 3 elements then set n(AXB) is a) 12 b) 14 c) 24 d) 7

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Answer:

The correct option is a.

Step-by-step explanation:

Given information:

Number of elements in set A = 4

Number of elements in set B = 3

We need to find n(A × B). It means we have to find the number of elements in set A × B.

If P and Q are two sets with elements m and n respectively, then the number of element in the set P × Q is m × n.

$n(A\times B)=n(A)\times n(B)$

$n(A\times B)=4\times 3$

$n(A\times B)=12$

The value of n(A × B) is 12. Therefore the correct option is a.

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