Question

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 !!!!!!

Answer 1

Answer:

$\boxed{ \sf{ \bold{1. \: \: \: x = 5}}}$

$\boxed{ \sf{ \bold{2. \: \: x = 6}}}$

$\boxed{ \bold{ \sf{3. \: \: x = 21}}}$

Step-by-step explanation:

1. $\sf{3x + 6 = 21}$

Move constant to right hand side and change its sign

⇒$\sf{3x = 21 - 6}$

Subtract 6 from 21

⇒$\sf{3x = 15}$

Divide both sides of the equation by 3

⇒$\sf{ \frac{3x}{3} = \frac{15}{3} }$

Calculate

⇒$\sf{x = 5}$

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2. $\sf{33 = 7x - 9 }$

Swap the sides of the equation

⇒$\sf{7x - 9 = 33}$

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

⇒$\sf{7x = 33 + 9}$

Add the numbers

⇒$\sf{7x = 42}$

Divide both sides of the equation by 7

⇒$\sf{ \frac{7x}{7} = \frac{42}{7} }$

Calculate

⇒$\sf{x = 6}$

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3. $\sf{28 = 7 + x}$

Swap the sides of the equation

⇒$\sf{7 + x = 28}$

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

⇒$\sf{x = 28 - 7}$

Subtract 7 from 28

⇒$\sf{x = 21}$

Hope I helped!

Best regards!!