I hope this helps you
2y+y=9
3y=9
y=3
x=2y=2.3=6
Supplementary means it adds up to 180 degrees.
So if one side is 31 degrees, you would need to subtract that from 180 to find the other side.
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180 - 31 = 149
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The other angle would be 149 degrees.
Answer:

Step-by-step explanation:
The standard form of a quadratic is
. You need to subtract the x^2 from the right to set the quadratic equal to 0. Then a,b, and c are equal to the values of the coefficients in front of the terms.
If this helped, a brainliest would be greatly appreciated!
You're trying to find constants

such that

. Equivalently, you're looking for the least-square solution to the following matrix equation.

To solve

, multiply both sides by the transpose of

, which introduces an invertible square matrix on the LHS.

Computing this, you'd find that

which means the first choice is correct.