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2 years ago

Select proportional or not proportional to correctly classify the pair of ratios. 1.2/3 and 1.8/4.5

Mathematics

2 answers:

satela [25.4K]2 years ago

8 0

Answer:Proportional

Step-by-step explanation:

Gnesinka [82]2 years ago

6 0

Answer:

Proportional.

Step-by-step explanation:

Find the cross products. If they are same, then they are proportional.

$\dfrac{1.2}{3} = \dfrac{1.8}{4.5}$

Cross multiply,

1.2 * 4 .5 = 3*1.8

5.40 = 5.4

So, they are proportional.

Multiply the numerator and denominator of 1.2/3 by 1.5

$\dfrac{1.2*1.5}{3*1.5}=\dfrac{1.8}{4.5}$

From this we come to know they are proportional

1.2 : 3 :: 1.8 : 4.5

Product of means = 3*1.8 = 5.4

Product of extremes = 1.2*4.5 = 5.4

Product of means = product of extremes. So, they are proportional.

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Answer:

(5,10)

Step-by-step explanation:

Midpoint = (x1+x2)/2 , (y1+y2)/2

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3 years ago

Rewrite the expression −7/8 − 2 1/4 as the sum of two numbers.

pychu [463]

Answer:

-3 1/8.

Step-by-step explanation:

−7/8 − 2 1/4

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3 years ago

Solve the equation for all real values of x.<br> cosxtanx - 2 cos x=-1

IceJOKER [234]

Solution to equation $cosxtanx - 2 cos^2 x=-1$ for all real values of x is $x=2k\pi + \frac{\pi}{6} , x=2k\pi + \frac{5\pi}{6}$ .

<u>Step-by-step explanation:</u>

Here we have , $cosxtanx - 2 cos^2 x=-1$ . Let's solve :

⇒ $cosxtanx - 2 cos^2 x=-1$

⇒ $cosx(\frac{sinx}{cosx}) - 2 cos^2 x=-1$

⇒ $sinx = 2 cos^2 x-1$

⇒ $sinx = 2 (1-sin^2x)-1$

⇒ $sinx = 1-2sin^2x$

⇒ $2sin^2x+sinx-1=0$

By quadratic formula :

⇒ $sinx = \frac{-b \pm \sqrt{b^2-4ac} }{2a}$

⇒ $sinx = \frac{-1 \pm \sqrt{1^2-4(2)(-1)} }{2(2)}$

⇒ $sinx = \frac{-1 \pm3}{4}$

⇒ $sinx = \frac{1}{2} , sinx =-1$

⇒ $sinx = sin\frac{\pi}{6} , sinx = sin\frac{3\pi}{2}$

⇒ $x=\frac{\pi}{6} , x=\frac{3\pi}{2}$

But at $x=\frac{3\pi}{2}$ we have equation undefined as $cos\frac{3\pi}{2}=0$ . Hence only solution is :

⇒ $x=\frac{\pi}{6}$

Since , $sin(\pi -x)=sinx$

⇒ $x=\pi -\frac{\pi}{6} = \frac{5\pi}{6}$

Now , General Solution is given by :

⇒ $x=2k\pi + \frac{\pi}{6} , x=2k\pi + \frac{5\pi}{6}$

Therefore , Solution to equation $cosxtanx - 2 cos^2 x=-1$ for all real values of x is $x=2k\pi + \frac{\pi}{6} , x=2k\pi + \frac{5\pi}{6}$ .

3 0

3 years ago

Simplify the equation -4d - 37 = 7d + 18

exis [7]

Answer:

d=-5

Step-by-step explanation:

-4d-37=7d +18

move the terms to its correct side

-4d-7d=18+37

calculate the like terms together.

-11d=55

divide both sides by -11. both of the negavtive (-11) will cancel out and become d on the left and on the right 55 will be divided by -11 = -5. the 5 is negative because there's a negative -11 if there were a postive 11 it will be 5 instead of D=-5

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3 years ago

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const2013 [10]

Answer:

Step-by-step explanation:

The vertex is the turning point of the quadratic function.

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6 0

3 years ago

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