+449 Which values of x make the inequality 4x < 12 true?
Because x<3, x<7 and x<12 means that x can be as small as we want 4*x can be smaller than 12 (thereby 4x<12), however, when x>7 $${\mathtt{4}}{\mathtt{\,\times\,}}{\mathtt{7}} = {\mathtt{28}}$$ the answer cannot be smaller than 28, so only that one does not make the inequality true
