You can put this solution on YOUR website! Start by making the translation from English to math.
"The sum" means to add.
"Four times a number" means 4 times an unknown number, which we usually call 'x'. So, it is 4x.
That is the first element of the "sum."
"and 3" means +3.
"is eleven" means = 11.
So, we have the parts of the addition now:
.
Done.