Answer:
E
Step-by-step explanation:
let a, b, c represent the number of students in 6th, 7th, 8th grade
ratio of students : teachers = 28 : 1
There are 82 teachers , so 28 × 82 = 2296 students
Then
a + b + c = 2296 , that is
828 + b + c = 2296 ( subtract 828 from both sides )
b + c = 1468 → E
Let y = 12 e^2x
e^2x = y/12
Taking
[email protected]ln e^2x = ln (y/12)
2x = ln (y/12)
x = (1/2) ln (y / 12)
so the inverse h-1(x) = (1/2) ln ( x / 12)
Answer:
290
Step-by-step explanation:
60% of ⅔X = 174
60/100 × 2/3 × X = 174
⅖X = 174
X = 435
⅔X = ⅔×435
290
290 cars are left in the parking,
145 cars left
Answer:
e. 10√30
Step-by-step explanation:
In this right triangle geometry, all of the right triangles are similar. This means that the ratio of long side to hypotenuse is the same for all triangles:
x/(10+50) = 50/x
Multiplying by 60x, we have ...
x^2 = 3000
x = 10√30 . . . . . take the square root. Matches choice E.
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<em>Comment on estimating</em>
You're looking for x. Examining the figure, you see that x is the long side of the triangle with hypotenuse 10+50=60, so it will be shorter than that value. x is also the hypotenuse of the triangle with long side 50. So, x will be longer than 50.
The only answer choice with a value between 50 and 60 is choice E.
You don't even need to know how to find x. You only need to know that the hypotenuse is the longest side in a right triangle.
Remark
The point value is (-2,5) So we know the two sides. We need the hypotenuse. We should notice that the x value is minus (-2) and value is y value is plus (5). That means we are in quad 2. Be careful how you read that. (-2,5) is a point. It is not a tangent.
Step One
Find the hypotenuse.
a = - 2
b = 5
c = ??
c^2 = a^2 + b^2
c^2 = (-2)^2 + 5^2
c^2 = 4 + 25
c^2 = 29 Take the square root of both sides.
sqrt(c^2) = sqrt(29)
c = sqrt(29)
Step Two
Find the Cosine of the angle.
Cosine(theta) = adjacent / hypotenuse
Cosine(theta) = -2 / sqrt(29) <<<<<<< Answer
Again, watch out for what you are given.