proyaop

y = the height, so we can plug in 18 for y.

\(-4.9t^2 + 23.8t = 18\)

Then we turn this into a quadratic.

\(-4.9t^2 + 23.8t - 18 = 0\)

Then we can use the quadratic formula \(t = {-b \pm \sqrt{b^2-4ac} \over 2a}\), where a is the coefficient of t^2, b is the coefficient t, and c is the constant.

Plugging in the values we get: approximately 3.92 second

the answer is 3.92004 :) 

Half of 75 is 37.5.

Half of "???" is 1.5 x "?".

First of all, if we have a trapezoid with bases BC and AD, then DB would be a diagonal. And DBA is the same angle as ABD, so they can't be different angles. In your problem, it says DBA = 105, and ABD = 43, but they are the same angle and 105 is not equal to 43. I think what you might mean is that the 3 interior angles of the trapezoid are 105, 43, and 147 degrees.

If that is so, then angle CBD is 360 - (105 + 43 + 147) = 165 degrees.

Also that wouldnt be a trapezoid. 

You could observe it, if it is solid, it would have a solid form and you could feel it and it would be hard, if its liquid it would be oozy or drip around, and you could put your hand through it, if it is a gas you can see it, or smell it. To know what a specific element is at, at room temperature, you can either search it up, or do an experiment. And sometimes it just is hard to tell. 

Science related questions 

To make it clearer, we can see that the midpoints of the octagon and the vertices create 16 congruent triangles, thus ABMO consists of 3 congruent triangles and MCDEO consists of 5 of them, thus the answer is 3/5.

If angle BEF is 120 degrees, then angle FEG + anglex = 60 degrees. Using alternate interior angles, angle EFG is 120 degrees, and angle FEG = 60/2 = 30 degrees, so angle x = 30 degrees.

Since triangle PDC is an isosceles triangle, and AB is parallel to DC because it is a rectangle, then that means angle DCP is congruent to angle BAC. So angle PCD is 21*. Angle PDC is also 21*.

Angle DAQ is 90 - 21 = 69*. So QDA is 180-90-69 = 21 degrees. Since we are looking for the sum of angles PDC and angle QDA, the answer is 42*.

Since we know the angles of the parallelogram are 45*, 135*, 45*, 135*, and the area of a parallelogram is base x height, we can draw an altitude from point X down to segment YZ. This creates a 45-45-90 triangle with hypotenuse 18. Thus, the side length of this triangle would be 9sqrt(2). That means the height of the parallelogram WXYZ is 9sqrt(2), since the base is 10, we can do base x height, or 10 x 9sqrt(2)

Thus, the area of the parallelogram is \(90\sqrt2\).

First let's try and factor what we can first. Since the coefficient of m is -6, then we know that the first part of the parenthesis when factored should look something like this:

(3m _ _)(n _ _)

Then we can plug in some values, since we know that the coefficient of m is -6, we divide -6 by 3, and get -2. Then the expression is:

(3m _ _)(n - 2)

Since the coefficient of n is 7, then the expression is:

(3m + 7)(n - 2).

When done factoring, the expression should look like:

\((3m+7)(n-2)\)

Once the parenthesis are opened, you will see that the constant is -14.