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3 years ago

Find the difference 12-20.5

Mathematics

2 answers:

myrzilka [38]3 years ago

7 0

The difference is 8.5

choli [55]3 years ago

4 0

The answer is -8.5. Hope this helps!

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Help, I don't remember

GenaCL600 [577]

Answer:

x = 144

Step-by-step explanation:

What you need to remember about this geometry is that all of the triangles are similar. As with any similar triangles, that means ratios of corresponding sides are proportional. Here, we can write the ratios of the long leg to the short leg and set them equal to find x.

x/60 = 60/25

Multiply by 60 to find x:

x = (60·60)/25

x = 144

_____

Comment on this geometry

You may have noticed that the above equation can be written in the form ...

60 = √(25x)

That is, the altitude from the hypotenuse (60) is equal to the geometric mean of the lengths into which it divides the hypotenuse (25 and x).

This same sort of "geometric mean" relation holds for other parts of this geometry, as well. The short leg of the largest triangle (the hypotenuse of the one with legs 25 and 60) is the geometric mean of the short hypotenuse segment (25) and the total hypotenuse (25+x).

And, the long leg of the large triangle (the hypotenuse of the one with legs 60 and x) is the geometric mean of the long hypotenuse segment (x) and the total hypotenuse (25+x).

While it can be a shortcut in some problems to remember these geometric mean relationships, you can always come up with what you need by simply remembering that the triangles are all similar.

3 0

3 years ago

If p varies directly with q, and p = 10 when q = 5, what is the value of p when q = 20

Inessa [10]

The value of p would be 40. This is because the ratio of p:q = 10:5. this could be simplify into p:q = 2:1. Applying the ratio p:20 = 2:1, P=40.

8 0

3 years ago

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brilliants [131]

Answer:

(a) x=2, y=-1

(b) x=2, y=2

(c) $\displaystyle x=\frac{5}{2}, y=\frac{5}{4}$

(d) x=-2, y=-7

Step-by-step explanation:

Cramer's Rule

It's a predetermined sequence of steps to solve a system of equations. It's a preferred technique to be implemented in automatic digital solutions because it's easy to structure and generalize.

It uses the concept of determinants, as explained below. Suppose we have a 2x2 system of equations like:

$\displaystyle \left \{ {{ax+by=p} \atop {cx+dy=q}} \right.$

We call the determinant of the system

$\Delta=\begin{vmatrix}a &b \\c &d \end{vmatrix}$

We also define:

$\Delta_x=\begin{vmatrix}p &b \\q &d \end{vmatrix}$

And

$\Delta_y=\begin{vmatrix}a &p \\c &q \end{vmatrix}$

The solution for x and y is

$\displaystyle x=\frac{\Delta_x}{\Delta}$

$\displaystyle y=\frac{\Delta_y}{\Delta}$

(a) The system to solve is

$\displaystyle \left \{ {{x+y=1} \atop {x-2y=4}} \right.$

Calculating:

$\Delta=\begin{vmatrix}1 &1 \\1 &-2 \end{vmatrix}=-2-1=-3$

$\Delta_x=\begin{vmatrix}1 &1 \\4 &-2 \end{vmatrix}=-2-4=-6$

$\Delta_y=\begin{vmatrix}1 &1 \\1 &4 \end{vmatrix}=4-3=3$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{-6}{-3}=2$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{3}{-3}=-1$

The solution is x=2, y=-1

(b) The system to solve is

$\displaystyle \left \{ {{4x-y=6} \atop {x-y=0}} \right.$

Calculating:

$\Delta=\begin{vmatrix}4 &-1 \\1 &-1 \end{vmatrix}=-4+1=-3$

$\Delta_x=\begin{vmatrix}6 &-1 \\0 &-1 \end{vmatrix}=-6-0=-6$

$\Delta_y=\begin{vmatrix}4 &6 \\1 &0 \end{vmatrix}=0-6=-6$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{-6}{-3}=2$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{-6}{-3}=2$

The solution is x=2, y=2

$\displaystyle \left \{ {{-x+2y=0} \atop {x+2y=5}} \right.$

Calculating:

$\Delta=\begin{vmatrix}-1 &2 \\1 &2 \end{vmatrix}=-2-2=-4$

$\Delta_x=\begin{vmatrix}0 &2 \\5 &2 \end{vmatrix}=0-10=-10$

$\Delta_y=\begin{vmatrix}-1 &0 \\1 &5 \end{vmatrix}=-5-0=-5$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{-10}{-4}=\frac{5}{2}$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{-5}{-4}=\frac{5}{4}$

The solution is

$\displaystyle x=\frac{5}{2}, y=\frac{5}{4}$

(d) The system to solve is

$\displaystyle \left \{ {{6x-y=-5} \atop {4x-2y=6}} \right.$

Calculating:

$\Delta=\begin{vmatrix}6 &-1 \\4 &-2 \end{vmatrix}=-12+4=-8$

$\Delta_x=\begin{vmatrix}-5 &-1 \\6 &-2 \end{vmatrix}=10+6=16$

$\Delta_y=\begin{vmatrix}6 &-5 \\4 &6 \end{vmatrix}=36+20=56$

$\displaystyle x=\frac{\Delta_x}{\Delta}=\frac{16}{-8}=-2$

$\displaystyle y=\frac{\Delta_y}{\Delta}=\frac{56}{-8}=-7$

The solution is x=-2, y=-7

4 0

3 years ago

How would you write odds in favor?

Andrews [41]

Answer: Odds in favor = Number of successes: Number of failures

Step-by-step explanation:

Example

A jewelry box contains 5 white pearl, 2 gold rings and 6 silver rings. What are the odds of drawing a white pearl from the jewelry box?

Number of successes = 5

Number of failures = 2 + 6 = 8

Numbers of ways to draw a white pearl: number of ways to draw another jewelry.

5:8

The odds are 5:8

3 0

3 years ago

What is the exact solution of cos (17pi/6)?

kolbaska11 [484]

The exact solution of cos (17π/6) is as follows:

First change the angle into degrees.

17(π/6) (180°/π) = 510°

Then we calculate the cosine of the angle above and it as follows:

cos 510° = -(√3)/2

Hope this answers the question. Have a nice day.

4 0

3 years ago