L = number of laptops bought
T = number of tablets bought
ok.. so, we know there are 30 salespeople.... so... the business is getting 30 of devices.. .so, whatever L is and T is, we know L + T = 30
each laptop is 515 bucks, so if they buy L amount, they'd end up paying 515*L or 515L bucks
each tablet is 285, so if they buy T tablets they'd end up paying 285*T or 285T bucks for them.
whatever those may be, we know all they have is 11,080. so 515L + 285T = 11080
[tex]\bf \begin{cases}
L+T=30\implies \boxed{T}=30-L\\
515L+285T=11080\\
----------\\
515L + 285\left( \boxed{30-L} \right)=11080
\end{cases}[/tex]
solve for L, to see how many laptops they'd get.
what about the tablets? well, T = 30 - L.
