Answer:
(2,-5)
Step-by-step explanation:
See attachment
One can also solve this by calculation:
y=2x-9
y=-2x-1
-
Rearrange either equation to find x. I'll use the first:
y=2x-9
2x = y+9
x = (y+9)/2
Now use this value of x in the second equation:
y = -2x-1
y =-2((y+9)/2)-1
y = (-2y-18)/2)-1
y = -y -9 - 1
2y = -10
y = -5
Now use -5 for y in the rearranged equation:
y = -2x-1
-5 = -2x-1
-2x = -4
x = 2
Solution is (2,-5)
But the question wants a graph solution, which is also fun when you use DESMOS.
Mean = (8 + 9 + 10 + 16 + 17) / 5 = 60/5 = 12.
x - mean:
8 - 12 = -4, -4² = 16
<span>9 - 12 = -3, -3² = 9
</span>
<span>10 - 12 = -2, -2² = 4
</span>
<span>16- 12 = 4, 4² = 16</span>
<span>17- 12 = -5, -5² = 25
</span>
Sum of the squares = 16 + 9 + 4 + 16 +25 = 70
Variance = 70/5 = 14
Variance = 14