lets read the question in parts :
Four times the sum of a number and two
So 4 times what ?
4 times sum of a number and two
assume our number is x , So this above sentence is converted to
Second part of the question
is nine less than five times the same number
So combing both half's of the statement
We get 4*(x+2) = 5x-9
That if you open up the brackets and simplify then reduces to
4x+8 = 5x - 9
5x-4x = 8+9
Hope this helps !! break the sentence in two half's and build a relationship !