The answer to the question is b
Answer:
x = 1, y = -4
Step-by-step explanation:
7х + 2y = -1 ------ eq1
3х — 4y = 19 ------ eq2
multiply eq1 by 2
2 x (7х + 2y = -1)
14x + 4y = -2 -----eq3
by elimination, add equation 2 and 3
14x + 3x = 19-2
17x = 17 (divide both sides by 17)
x = 1 (answer)
substitute into eq1
7(1) + 2y = -1 (subtract 7 from both sides)
2y = -1 -7
2y = -8 (divide both sides by 2)
y = -8/2 = -4 (answer)
We have that
set of data [<span>8, 12, 15, 17, 18]
step 1
Find the mean
</span>[8+ 12 + 15 + 17 + 18]/5-------> 70/5------> 14
step 2
for each number: subtract the Mean and square the result
(8-14)²----->36
(12-14)²----> 4
(15-14)²----> 1
(17-14)²----> 9
(18-14)²----> 16
step 3
<span> work out the mean of those squared differences
[36+4+1+9+16]/5-----> 66/5-----> 13.2----> </span><span>this value is called the "Variance"
step 4
</span><span>Take the square root of that
</span>standard desviation=√13.2-----> 3.63-------> 4
the answer is
4
12 Cells . 6 Because You're Doing Half A Hour For 3 Hours . Then Multiply By 2 . This Answer Will Land You A 6 .
