A is definitely the answer.
Answer: x = 1, y = -2
Step-by-step explanation:
-9x+2y=-13
x= 13/9 + 2/9y
2x-9y=20
2(13/9+2/9y)-9y=20
<em>Substitute y with -2.</em>
<em />
x= 13/9+2/9(-2)
<em>After solving you'll see that 1 is a possible solution for x.</em>
<em />
Check your answer
-9x+2y=-13
-9x1+2(-2) = -13
2x-9y=20
2x1-9(-2) = 20
-13 = -13
20 = 20
Therefore, x=1 and y=-2
This can help you
a) since it is discrete we need to think about the sum thing
it it was continuous we would look at an integral thing
so I think if I remember correctly we need to find c such that
<span><span>∑<span>i=0</span>3</span>c(<span>x2</span>+4)=1
b) </span>
problem b is a similar setup