Find the average..............?
Find the average......................? The 45 students in a class each recorded the number of whole minutes, x, spent doing experiments on Monday. The results are total x= 2230 Find the mean number of minutes the students spent doing experiments on Monday. ^that one i can do, but its the next one i dont know two new students joined the class and reported that they spent 37 minutes and 30 minutes respectively. calculate the new mean including these two students.
Help with direct variation? 1.if y =45 when x=15 find x when y = 15.same for these 2.y=-4 x=2 --x=-6 ?
1.if y=45 when x=15 find x when y = 15.same for these For all of these questions, only a single point is given, which implies that "direct variation" means "linear with a y-intercept of zero". Thus, the equation passing through the first point is: y = 3x Solving for y=15: y = 3x 15 = 3x 5 = x Thus, the answer is 5. 2.y=-4 x=2 --x=-6 ? Similarly, the equation and solution is: y = -2x y = -2(-6) y = 12 3.y=-9 x=3--x=-5 y = -3(x) y = -3(-5) y = 15 4.y=4 x=16--x=6 y = (1/4)*x y = (1/4)*6 y = 3/2 5.y=12 x=18--x=-16 y = (2/3)x y = (2/3)*(-16) y = -32/3
9 - 6x = 45 find the value of x-4???? Help please!!?
ok so 9 - 6x = 45 you subtract like terms so subtract 9 from 45 and it should now look like -6x = 36 divide -6x and 36 and it now looks like x = -6 so if x-4 and x= -6 it would look like - 6 - 4 a negative MINUS a positive is a negative so the answer is -10
ALGEBRA HELP. my work is due on the 9th of feb!?
It doesn't help you learn if others do your homework for you. I'll do the first one for you, try the rest on your own. 1. Say that the larger number is x, and the smaller number is y. The first bit of information we have is that the larger number is 5 times the smaller number, so we set up our equation of x=5y. We also know that the sum of the two numbers is 54, so we have another equation, x+y=54. Solve for one of the equations for one of the variables, in this case x, so that you can find x, which is the larger number, and substitute that in to the other equation. For ex: x+y=54 -x -x y=54-x x=5y x=5(54-x) x=270-5x +5x +5x 6x=270 /6 /6 x=45, the larger number. Just remember, set up your equations, solve for one of the variables, and substitute that into the other equation, then solve. That should get you through the rest of your problems, good luck!
QUICK MATH HELP!!!!!!!!!!!! Please, it'll be quick!?
The price to produce (x) candles is given by C(x) = 115 + 0.9x What is the cost of producing the 45th unit? -------------------- I tried substituting 45 to x in the equation but it doesn't work!
Find the value of x and y. Show all work.?
From looking at the angles, I got x + 3y = 45, and (x + 3y) + 60 + (5x - y) = 180. So, 45 + 60 + (5x - y) = 180. So, 5x - y = 75. I solved the following system: x + 3y = 45. 5x - y = 75. Multiplied this by 3. x + 3y = 45 15x - 3y = 225. So, 16x = 270. x = 16.875. 16.875 + 3y = 45. 3y = 45 - 16.875. y = 9.375. Solution set: (x, y) is (16.875, 9.375). Hope this helps!
Find the value of x in the equation sqrt of (x) +5= sqrt (x+45 )?
√x + 5 = √(x + 45) (Square both sides) (√x + 5)² = x + 45 (Square the binomial) x + 10√x + 25 = x + 45 x - x + 10√x = 45 - 25 10√x = 20 (Divide both sides by 10) √x = 2 (Square both sides) x = 4 (Answer) Pick b. Hope this helps!
Find the x intercepts of the parabola with vertex (1,45) and y intercept (0,40)?
y= a(x - 1)^2 + 45 40 = a(0 -1)^2 + 45 40= a(-1)^2 + 45 40 = 1a + 45 -5 = 1a a = -5 y= -5(x - 1)^2 + 45 y= -5(x^2 - 2x + 1) + 45 y= -5x^2 + 10x -5 + 45 y= -5x^2 + 10x + 40.........the calculator listed below has a factor function on its sidebar y= -5(x^2 - 2x - 8) y= -5(x - 4)(x + 2) x = 4 and x = -2 are the two x-intercepts http://www.ecalc.com/
Find the values of x such that the angle between the vectors <2, 1, -1> and <1, x, 0> is 45?
cos(theta) = a.b / (|a|*|b|). Let a = <2,1,-1> , b = <1,x,0> So we first take the dot product of the two: a.b = 2 + x. Then we find the magnitudes of the two vectors. |a| = sqrt (6), |b| = sqrt(1+x^2) Now for the angle between the two vectors to be 45 degrees, we substitute 45 degrees into cosx and try to find x. cos(45) = 1/sqrt(2) Now we substitute everything back into the first equation: 1/sqrt(2) = (2+x) / sqrt(6+6x^2) So sqrt(6+6x^2) = (2+x) * sqrt(2). sqrt(3+3x^2) = 2+x (I divided by sqrt(2) on both sides) 3+3x^2 = 4+4x+x^2 (square both sides) 2x^2 -4x-1 = 0 which gives you x = 1 + (sqrt(6)/2), x = 1 - (sqrt(6)/2)