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3 years ago

HELP FOR 20 POINTSSS

Mathematics

1 answer:

Monica [59]3 years ago

4 0

Answer:

The first one.

Step-by-step explanation:

solving for x:

5/2 = 7.5/x

cross multiply

2 ×7.5 =5x

x= 2×7.5/5

x= 3

solving for y:

values of the small triangle over the bigger triangle-

5/6 =7/y

cross multiply and solve for y

y= 8.4

therefore (x= 3; y= 8.4)

YOU ARE VERY WELCOME!

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Pedro simplified 4/7 5/8 his work is shown below identify where he made his error

motikmotik

4/7 cannot be simplified anymore. 5/8 can't be simplified either.

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3 years ago

Change 2.56 into a percentage * 0.0256% 25.6% 256.0% none of the above

Ksivusya [100]

Answer:

C: 256%

Step-by-step explanation:

8 0

2 years ago

Read 2 more answers

MATH HELP PLZ!!!

RoseWind [281]

Answer:

a) $tan (157.5) = \frac{1-cos 315}{sin315}$

$sin (165) =\sqrt{ \frac{1-cos (330) }{2}}$

$sin^{2} (157.5) = \frac{1-cos (315) }{2}$

cos 330° = 1- 2 sin² (165°)

Step-by-step explanation:

Step(i):-

By using trigonometry formulas

cos2∝ = 2 cos² ∝-1

cos∝ = 2 cos² ∝/2 -1

1+ cos∝ = 2 cos² ∝/2

$cos^{2} (\frac{\alpha }{2}) = \frac{1+cos\alpha }{2}$

cos2∝ = 1- 2 sin² ∝

cos∝ = 1- 2 sin² ∝/2

$sin^{2} (\frac{\alpha }{2}) = \frac{1-cos\alpha }{2}$

Step(i):-

Given

$tan\alpha = \frac{sin\alpha }{cos\alpha }$

we know that trigonometry formulas

$sin\alpha = 2sin(\frac{\alpha }{2} )cos(\frac{\alpha }{2} )$

1- cos∝ = 2 sin² ∝/2

Given

$tan(\frac{\alpha }{2} ) = \frac{sin(\frac{\alpha }{2} )}{cos(\frac{\alpha }{2}) }$

put ∝ = 315

$tan(\frac{315}{2} ) = \frac{sin(\frac{315 }{2} )}{cos(\frac{315 }{2}) }$

multiply with ' 2 sin (∝/2) both numerator and denominator

$tan (\frac{315}{2} )= \frac{2sin^{2}(\frac{315)}{2} }{2sin(\frac{315}{2} cos(\frac{315}{2}) }$

Apply formulas

$sin\alpha = 2sin(\frac{\alpha }{2} )cos(\frac{\alpha }{2} )$

1- cos∝ = 2 sin² ∝/2

now we get

$tan (157.5) = \frac{1-cos 315}{sin315}$

$sin^{2} (\frac{\alpha }{2}) = \frac{1-cos\alpha }{2}$

put ∝ = 330° above formula

$sin^{2} (\frac{330 }{2}) = \frac{1-cos (330) }{2}$

$sin^{2} (165) = \frac{1-cos (330) }{2}$

$sin (165) =\sqrt{ \frac{1-cos (330) }{2}}$

c )

$sin^{2} (\frac{\alpha }{2}) = \frac{1-cos\alpha }{2}$

put ∝ = 315° above formula

$sin^{2} (\frac{315 }{2}) = \frac{1-cos (315) }{2}$

$sin^{2} (157.5) = \frac{1-cos (315) }{2}$

cos∝ = 1- 2 sin² ∝/2

put ∝ = 330°

$cos 330 = 1 - 2sin^{2} (\frac{330}{2} )$

cos 330° = 1- 2 sin² (165°)

3 0

3 years ago

Alex drew a scale drawing of an auditorium. He used the scale 3 inches = 2 feet. If the stage is 30 inches in the drawing, how w

White raven [17]

Answer:

20 feet

Step-by-step explanation:

The scale is 3 inches is to 2 feet

As a ratio, it would be:

$\dfrac{3}{2}$

The question is what is the actual length of the stage if the drawing is 30 inches. All we need to do is find a ratio proportional to the scale ratio:

$\dfrac{3inches}{2feet} = \dfrac{30inches}{xfeet}$

Now to find the missing number, cross multiply the fractions first:

$\dfrac{3}{2}=\dfrac{30}{x}$

$(3)(x)=(2)(30)$

$3x=60$

Then solve for x:

$3x=60$

$x=\dfrac{60}{3}$

$x=20$

The answer is 20 feet

8 0

3 years ago

What is the y intercept of the line? X=24,36,48 and y= -8, 1, 10

goldenfox [79]

Answer:

y intercept = - 40

Step-by-step explanation:

x 24 36 48

y -8 1 10

y = ax + b

a is the gradient (or slope).

b = y intercept.

a = (48-36) / (10-1) = 12/9

Rewrite to solve for b, which means it starts with b = ...

b = y - 12/9 * x

Substitute one point ( 24 , -8 )

b = -8 - (12/9 * 24)

b = y intercept = - 40

4 0

3 years ago