[(3a+1)x]/3=[a(x-4)]/4(x是未知数)

问题描述:

[(3a+1)x]/3=[a(x-4)]/4(x是未知数)

[(3a+1)x]/3=[a(x-4)]/4
4(3a+1)x=3ax-12a
12ax-3ax+4x=-12a
9ax+4x=-12a
(9a+4)x=-12a
x=-12a/(9a+4)