When it says "when x = 7" this instantly means you should evaluate.
You are going to plug in the number "7", which means the variable "x" is going to become "7":
\(7.5(3x+4)\)
\(7.5((3)(7)+4)\)
So, now what you're going to do is MULTIPLY 3 and 7:
(Note: Remember PEMDAS, work in the Parenthesis first)
\(3*7=21\)
So, now your problem should look like this:
\(7.5(21 + 4)\)
Next step is to add 21 and 4, (We are still working in Parenthesis):
\(21+4=25\)
Final step, you are going to Multiply 7.5 and 25 to get your answer, like this:
\(7.5*25=187.5\)
Your correct answer is:
\(187.5\)
Good luck with your studies, I hope this helps~!
