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3 years ago

Can somebody please help with these two? I'll mark brainliest for your answer!

Mathematics

1 answer:

vlada-n [284]3 years ago

5 0

Answer:

1. $-40\dfrac{1}{2}$

2. $\frac{5}{8}$

Step-by-step explanation:

1. We are given an expression that is $3\dfrac{4}{5}x-2\dfrac{1}{2}$ . We have to find its value for x = - 10

So, $3\dfrac{4}{5}x-2\dfrac{1}{2}$

= $\frac{19x}{5} -\frac{5}{2}$

= $\frac{19}{5} \times(-10) -\frac{5}{2}$ {Putting the value of x}

= $-38 - \frac{5}{2}$

= $-\frac{81}{2}$

= $-40\dfrac{1}{2}$ (Answer)

2. $(-\frac{5}{6}) \times (-\frac{5}{8} )\times (\frac{6}{5} )$

= $\frac{5}{6} \times \frac{5}{8} \times \frac{6}{5}$

= $\frac{5}{8}$ (Answer){Since $\frac{a}{b} \times \frac{b}{c} =\frac{a}{c}$ }

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3 years ago

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4 years ago

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Step-by-step explanation:

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Also, if we know that the sin of angle is 3/4, we can set up a right triangle in QI and find the missing side of that triangle using Pythagorean's Theorem. Sin of an angle is the ratio opposite side/hypotenuse. That means that, according to Pythagorean's Theorem,

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Referring to the right triangle we created and found the missing side for, we see that the cosine of that same triangle is $\frac{\sqrt{7} }{4}$

Filling in the formula then:

$sin(\frac{\theta}{2})=\sqrt{\frac{1-\frac{\sqrt{7} }{4} }{2} }$

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$sin(\frac{\theta}{2})=\sqrt{\frac{\frac{4-\sqrt{7} }{4} }{2} }$

Bring up the 2 as 1/2 to multiply and get:

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Step-by-step explanation:

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2 years ago