Answer:
3(7+3m)=84
21+9m=84
9m=63
m=7
Step-by-step explanation:
hope it helps
Answer:

Step-by-step explanation:
You would substitute "2x" for every "x" in the function in the same way you would substitute any other number.
So if f(x)=Sqrt[7x²-3x], then: f(2x)=Sqrt[7(2x)²-3(2x)]
=Sqrt[7(4x²)-3(2x)]
=Sqrt[28x²-6x]
You would multiply both sides by 3 to cancel out the divide 3.
z÷3=8
z=24