8/13=2x/39 и 3/14=21/2(x+31) пж решите

8/13 = 2х/392х = 39•8/13 х = 3•8/2х = 3•4х =123/14 = 21/2(х+31)х+31 = 3/14 : 21/2х+31 = 3/14 • 2/21х+31 = (3•2)/(14•21)х+31 =(1•1)/7•7)х+31 = 1/49х = 1/49 - 31х = 1/49 -1519/49х = -1518/49х = -30 48/49