How to solve the inequality 4(x+3) < 60?

As we are working with an inequality we have to pay attention every time to the symbol, in this case less <, that rules the inequality. The first step to solve it, it is the expansion of the LHS, so we have 4(x +3 ) = 4x +12 < 60. Now as our aim is to obtain the value of x, we want to remove the 12 in the LHS. To do that, we have to be coherent and therefore subtract 12 in both sides of the inequality so: 4x +12 -12 < 60 -12. Finally this expression can be written as 4x < 48, where diving by 4 in both sides we simply obtain x <12 as our final result.