Question

a)       1/3 x * + 30 = 40           b) 3/5 * 49/18 * 25/14 * 12/7  

Answer 1

A) 1/3x + 30 = 40              B) 3/5 * 49/18 * 25/14 * 12/7 << só ir cortando
x/3 = 40-30                           corta o 5 com 25 e o 49 com o 7 fica:
x/3 = 10                               3/1*7/18*5/14*12/1  dai corta o 14 com o 12
x = 10*3                               3*7/19*5/7*6 corta 7 c/ 7
x=30                                     fica 3*1/19*5*6 = 90/19