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3 years ago

Please help

Mathematics

1 answer:

Ipatiy [6.2K]3 years ago

4 0

Answer:

cos (theta) = √21/5

Step-by-step explanation:

sin (theta) = 2/5

(sin (theta))^2 = 4/25

4/25 + (cos (theta))^2 = 1

(cos (theta))^2 = 1 - 4/25 = 21/25

cos (theta) = √21/5

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Marianna [84]

Answer:

x=-2

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Step-by-step explanation:

3=y+3x ---- A

-x+3y=29 ----B

step 1. rearrange equation A, so you have the "y" variable on one side

3=y+3x

-3x -3x

3-3x=y

y=3-3x ---- C

step 2. Substitute equation C into equation B in place of "y"

-x+3(3-3x)=29 ---foil

-x+9-9x=29 -- collect like terms

-10x+9=29

-9 -9

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Step 3. Substitute x=-2 into equation C to find y

y=3-3(-2)

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Check you answer by subsituting x=-2 and y=9 back into equation A and B

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Read 2 more answers

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3 years ago