Question

Determine o valor de x nas equações literais:         I) 3x+a=9a              II) 2x+3c=x+5c 

Answer 1

I)
3x+a=9a
3x=9a-a
3x=8a
x=8a/3
S={8a/3}

II)
2x+3c=x+5c
2x-x=5c-3c
x=2c
S={2c}

Answer 2

1)
 $3x + a = 9a \\ \\ 3x = 9a - a \\ \\ 3x = 8a \\ \\ x = \frac{8a}{3}$

2)

$2x+3c=x+5c \\ \\ 2x - x = 5c - 3c \\ \\ x = 2c$