Solve for x:
3 x+3/7 = 12
Put each term in 3 x+3/7 over the common denominator 7: 3 x+3/7 = (21 x)/7+3/7:
(21 x)/7+3/7 = 12
(21 x)/7+3/7 = (21 x+3)/7:
(21 x+3)/7 = 12
Multiply both sides of (21 x+3)/7 = 12 by 7:
(7 (21 x+3))/7 = 7×12
(7 (21 x+3))/7 = 7/7×(21 x+3) = 21 x+3:
21 x+3 = 7×12
7×12 = 84:
21 x+3 = 84
Subtract 3 from both sides:
21 x+(3-3) = 84-3
3-3 = 0:
21 x = 84-3
84-3 = 81:
21 x = 81
Divide both sides of 21 x = 81 by 21:
(21 x)/21 = 81/21
21/21 = 1:
x = 81/21
The gcd of 81 and 21 is 3, so 81/21 = (3×27)/(3×7) = 3/3×27/7 = 27/7:
Answer: |x = 27/7
