You can multiply either the top or bottom equation by -1 so lets say you apply it to the bottom equation it’ll look like this:
-9x + 9y = 18
6x - 9y = 12
then the +9y and -9y will cancel out
-9x = 18
6x =12
then you add the two equations together
-3x = 30
divide both sides by -3
x = -10
Answer:
<u>It</u><u> </u><u>is</u><u> </u><u>(</u><u>x</u><u> </u><u>-</u><u> </u><u>3</u><u>)</u><u>³</u><u> </u><u>-</u><u> </u><u>9</u><u>x</u><u>(</u><u>3</u><u> </u><u>-</u><u> </u><u>x</u><u>)</u>
Step-by-step explanation:
Express 27 in terms of cubes, 27 = 3³:

From trinomial expansion:

open first two brackets to get a quadratic equation:

expand further:

take y to be 3, then substitute:

<h3>
Answer: B) 2/3</h3>
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Explanation:
The order is important for ABC and XYZ so we can see what letters pair up.
- A pairs with X since they are the first letters
- B pairs with Y since they are the second letters
- C pairs with Z since they are the third letters
Based on that, we can see that AB pairs with XY as they are the first two letters of ABC and XYZ respectively.
Divide the length XY over AB and reduce
XY/AB = 10/15 = 2/3
We could also divide XZ over AC
XZ/AC = 14/21 = 2/3
and we get the same ratio
Because they will always be divisible by 5