Respuesta :

Answer:

a = 6

Step-by-step explanation:

120 = 3 + 3(7a - 3)   (by PEDMAS, expand parentheses first by distributive property)

120 = 3 + 7a(3) - 3(3)

120 = 3 + 21a - 9

120 = 21a - 6    (add 6 to both sides and rearrange)

21a = 120 + 6

21a = 126   (divide both sides by 21)

a = 126/21

a = 6

Step-by-step explanation:

120-(3+3*(7*a-3))=0

Step by step solution :

STEP

1

:

Equation at the end of step 1

120 - (3 + 3 • (7a - 3)) = 0

STEP

2

:

STEP

3

:

Pulling out like terms :

3.1 Pull out like factors :

126 - 21a = -21 • (a - 6)

Equation at the end of step

3

:

-21 • (a - 6) = 0

STEP

4

:

Equations which are never true:

4.1 Solve : -21 = 0

This equation has no solution.

A a non-zero constant never equals zero.

Solving a Single Variable Equation:

4.2 Solve : a-6 = 0

Add 6 to both sides of the equation :

a = 6

One solution was found :

a = 6