3(a− 6) = −5a− (7 + 3a)

A= 1

Step-by-step explanation:

Distribute

3 (  −  6 )  =  − 5  −  1  ( 7  + 3  )

3a - 18 = -5a - 1 ( 7 + 3a )

Rearrange terms

3  −  1 8  =  − 5  − 1  (  3  +  7  )

3a - 18 = -5a - 3a - 7

Combine like terms

3  −  1 8 = −5 −  3  −  7

3a - 18 = -8a - 7

Add  1 8 to both sides of the equation

3a - 18 = -8a - 7

3  −  1 8  +  1 8  =  − 8  −  7  +  1 8

Simplify

Add the numbers

3  −  1 8  +  1 8  =  − 8  −  7  +  1 8

3a = -8a - 7 + 18

Add the numbers  again

3  =  − 8  − 7  +  1 8

3a = -8a + 11

Add  8  to both sides of the equation

3a = -8a + 11

3  +  8  =  − 8  +  1 1  +  8

Simplify

Combine like terms

3  +  8  =  − 8  +  1 1  +  8

1 1  =  − 8  +  1 1  + 8

Combine like terms again

1 1  =  − 8  +  1 1  + 8

11a = 11

Divide both sides of the equation by the same term

11a = 11

1 1 / 1 1 = 1 1 /  1 1

Simplify

Cancel terms that are in both the numerator and denominator

1 1 / 1 1 = 1 1 /  1 1

a = 11/11

Divide the numbers

a = 11/11

a = 1

answer: it's d

step-by-step explanation:

d

step-by-step explanation:

i used the pitagoras theoreme