Answer:
12
Step-by-step explanation:
If there are 3 classrooms that each have 25 desks and there are a total of 87 students, how many more desks need to be added to a 4th classroom, that was originally empty, so that each of the students has a desk to sit in?
25 * 3 = 75
87 - 75 = 12
Answer:
B. x = 2, y = 6
Step-by-step explanation:
![2x + 5y = 34...(1) \\ \\ x + 2y = 14 \\ \therefore \: x = 14 - 2y...(2) \\ \\ from \: equations \: (1) \: and \: (2) \\ \\ 2(14 - 2y) + 5y = 34 \\ \therefore \: 28 - 4y + 5y = 34 \\ \therefore \: 28 + y = 34 \\ \therefore \: y = 34 - 28 \\ \huge \red{ \boxed{\therefore \: y = 6}} \\ substituting \: y = 6 \: in \: equation \: (2) \\ x = 14 - 2 \times 6 \\ \therefore \: x =14 - 12 \\ \huge \purple{ \boxed{\therefore \: x =2}} \\ \\ \huge \orange{ \boxed{ \therefore \: x = 2, \: \: y = 6}} \\](https://tex.z-dn.net/?f=2x%20%2B%205y%20%3D%2034...%281%29%20%5C%5C%20%20%5C%5C%20x%20%2B%202y%20%3D%2014%20%5C%5C%20%20%5Ctherefore%20%5C%3A%20x%20%3D%2014%20-%202y...%282%29%20%5C%5C%20%20%5C%5C%20from%20%5C%3A%20equations%20%5C%3A%20%281%29%20%5C%3A%20and%20%5C%3A%20%282%29%20%5C%5C%20%20%5C%5C%202%2814%20-%202y%29%20%2B%205y%20%3D%2034%20%5C%5C%20%5Ctherefore%20%5C%3A%2028%20-%204y%20%2B%205y%20%3D%2034%20%5C%5C%20%20%5Ctherefore%20%5C%3A%2028%20%2B%20y%20%3D%2034%20%5C%5C%20%5Ctherefore%20%5C%3A%20%20y%20%3D%2034%20-%2028%20%5C%5C%20%20%5Chuge%20%5Cred%7B%20%5Cboxed%7B%5Ctherefore%20%5C%3A%20%20y%20%3D%206%7D%7D%20%5C%5C%20substituting%20%5C%3A%20y%20%3D%206%20%5C%3A%20in%20%5C%3A%20equation%20%5C%3A%20%282%29%20%5C%5C%20x%20%3D%2014%20-%202%20%5Ctimes%206%20%5C%5C%20%5Ctherefore%20%5C%3A%20%20x%20%3D14%20-%2012%20%5C%5C%20%20%5Chuge%20%5Cpurple%7B%20%5Cboxed%7B%5Ctherefore%20%5C%3A%20%20x%20%3D2%7D%7D%20%5C%5C%20%20%5C%5C%20%5Chuge%20%5Corange%7B%20%5Cboxed%7B%20%5Ctherefore%20%5C%3A%20%20x%20%20%3D%202%2C%20%5C%3A%20%20%5C%3A%20y%20%3D%206%7D%7D%20%5C%5C%20)
Answer:
y=-3x+15
Step-by-step explanation:
the midpoint of UV (using the midpoint formula) is (3,6)
the slope of UV= 4/12= (1/3)
perpendicular slope is -3
now find line with slope -3 passing (3,6)
y-6=-3(x-3)
y=-3x+15
Answer:
C
Step-by-step explanation:
Technically there is a one here -1(5). Meaning its a positive