4x^2 + 5xy - y^2 = 6
Implicitly differentiating both sides,
4(2x) + 5(x y' + y) - 2yy' = 0
where y' = dy/dx
8x + 5xy' +5y -2yy' = 0
combining y' terms
y' (5x-2y) +8x +5y = 0
y'(5x-2y) = -(8x+5y)
dy/dx = -(8x+5y)/(5x-2y)
or
dy/dx = (8x+5y)/(2y-5x)
It should be :
1/3(x + 18) = 7
1/3x + 6 = 7
1/3x + 6 - 6 = 7 - 6
1/3x = 1
x = 3
Answer: 2.5 ft.
Step-by-step explanation: We know that the wall is 10ft and each poster is 1 1/4 ft, so subtract both posters from the wall, 10-2.5 = 7.5, then divide 7.5 by 3 since we need 3 lengths, and we get 2.5ft. So for x, it would be 2.5ft.
x=2.5
Hope this helps!
A. 4 city b 6
B. City a, 8, when rounded 10
City b, 12, when rounded 10
C. City A. 2, 3.5, 4, 4, 5.5, 5..... so it's 4
City B. 3.5, 4, 5, 5.5, 6, 6..... so it's 5.25
Sorry if this all wrong. I'm bad at this kind of stuff lol
Good luck
Answer:
B. A teacher compares the pre-test and post-test scores of students
Step-by-step explanation:
the answer is true, because it is a good example to compare the tests between students, we know that a matching pair design is a random model and is used when the experiment allows grouping subjects in pairs based on a variable and each pair will receive randomly a different handling, the answer A is not true because in the example all students are uniformly averaged and the variable is not correlated with subgroups, option c is incorrect because the variable was not randomized and generates classification bias and the option d is incorrect because the teacher compares a small sample as her class with a score of a total sample, but does not intervene on her students when selecting the corresponding group
