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

⇒

Subtract 6 from 21

⇒

Divide both sides of the equation by 3

⇒

Calculate

⇒

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2.

Swap the sides of the equation

⇒

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

⇒

Add the numbers

⇒

Divide both sides of the equation by 7

⇒

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

⇒

Hope I helped!

Best regards!!

diagonal is     or     16.97

step-by-step explanation:

from pythagorian theorem we know,

if a is perpendicular, b is base and c is hypotenuse,

then we get

now, for a square,

perpendicular and base are equal,

since all the sides of a square are equal.

so, we get,

this is the special version of pythagorian theorem for a square.

so, if the diagonal is d and length is 12 , then we get

by square rooting we get,