Just give the unknown number a name ... like 'Q' ... and then take the description phrase by phrase, one at a time:
"Five" . . . that one is pretty easy.
"4 times a number" . . . 4Q
"Five added to 4 times a number" . . . 5 + 4Q
"2 times the number" . . . 2Q
"9 less than 2 times the number" . . . 2Q - 9
The first quantity is equal to the second quantity . . . 5 + 4Q = 2Q - 9
That's choice D.
What if you had to solve it, and find the mysterious unknown number.
Could you handle it from here ?
5 + 4Q = 2Q - 9
Subtract 5 from each side: 4Q = 2Q - 14
Subtract 2Q from each side: 2Q = -14
Divide each side by 2 : Q = -7
-7 is the only number that will make that original long messy statement true.
