Answer
The statement is false.
Work Step by Step
The square of a binomial sum is: $(A+B)^2=A^2+2AB+B^2$.
Here: $(3x+5)^2=(3x)^2=2\cdot3x\cdot2+5^2=9x^2+30x+25$, thus because this is not equal to the left side of the equation, the statement is false.