​ Multiply.

(7x+3)(4x-5)

 

You take the first term in the first bracket and multiply it by the second bracket

 

so that is 7x     times by    (4x+5)

 

then you take the second term    +3   and multiply it by the second bracket.

 

If there were more terms would keep doing this but there are no more terms here.

So we have

 

7x(4x-5)      +3(4x-5)

 

now you just have to multiply out these brackets and then collect up the like terms. 

You do it and I will check you working :)