A special trick to solve this is using a method called FOIL
It tells you what terms to multiply
F= first two terms
O= The outer terms
I= The two inside terms
L= The two last terms
(2x+1)(3x+1)
Multiply 2x and 3x
6x²
Then 2x and 1
2x
Next 1 and 3x
3x
Lastly, multiply 1 and 1
1
You get an equation that looks like this
6x² + 3x +2x +1
Combine 3x and 2x because they are like terms
YOUR FINAL ANSWER = 6x² + 5x + 1
You can use the FOIL method for all problems like this