Solv for x for all of these 1. 3x+6=21 2. 33=7x-9 3. 28=7+x need to know now please help

Step-by-step explanation:

1.

Move constant to right hand side and change its sign

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Subtract 6 from 21

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Divide both sides of the equation by 3

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Calculate

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2.

Swap the sides of the equation

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Move constant to right hand side and change it's sign

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Add the numbers

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Divide both sides of the equation by 7

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Calculate

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3.

Swap the sides of the equation

⇒

Move constant to right hand side and change it's sign

⇒

Subtract 7 from 28

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Hope I helped!

Best regards!!

i believe that the answer is

b. y-1=-2(x-4)

hope this !