6(4 +2x) = 4(2x-1) + 4(x + 3) <= original equation

24 + 12x = 8x - 4 + 4x + 12 <= simplify by distribution

24 + 12x = 12x + 8 <= combine like terms on right side of equation (the x's - just add them together)

24 ≠ 8 <= subtract 12x from both sides; 24 does not equal 8

Now, when the result is two numbers that clearly do not equal each other, this is considered "no solution," or no valid solution for x. If, for example, you were left with 8 = 8, this is considered to be "all real numbers," meaning x can equal all real numbers, so x has an infinite numbers of answers!

Hope this helps! :-)

Source(s):
Honors Algebra II/Trig Student