Answer:8x^2+16x-24
Step-by-step explanation: Break this question into two parts
Solve (3x+1)^2 first
This is the same as (3x+1)(3x+1)
To expand the brackets we multiply the first term from the first bracket with the last bracket
3x(3x+1)=9x^2+3x
and the second term from the first bracket with the last bracket. 1(3x+1)=3x+1
This gives 9x^2+3x +3x+1..... combining the two together
Adding together like terms gives us the following:
9x^2+6x+1
Now we work on the second part
(x-5)^2=(x-5)(x-5)
Again using the same method, the first term of the first bracket with the last bracket
x(x-5)=x^2-5x
and the second term of the first bracket with the last bracket
-5(x-5)=-5x+25
Combining the two together gives us x^2-5x-5x+25
Simplifying the like terms gives us x^2-10x+25
Now we can simplify the original question by replacing each bracket with the values worked out
(3x+1)^2-(x-5)^2
9x^2+6x+1-(x^2-10x+25)
9x^2+6x+1-x^2+10x-25
8x^2+16x-24