Answer:
[tex]\left\{\begin{array}{l}x+y\ge 15\\ \\0.65x+0.78y<20\\ \\x\ge 0\\ \\y\ge 0\end{array}\right.[/tex]
Step-by-step explanation:
Let x be the number of apples and y be the number of oranges Kayla buys.
She needs to buy an assortment of at least 15 apples and oranges, then
[tex]x+y\ge 15[/tex]
Apples cost $0.65 each, then x apples cost $0.65x
Oranges cost $0.78 each, then y oranges cost $0.78y.
She spends less than $20.00, so
[tex]0.65x+0.78y<20[/tex]
Not that the number of apples and oranges must satisfy inequalities
[tex]x\ge 0\\ \\y\ge 0,[/tex]
so the following system of inequalities models this situation:
[tex]\left\{\begin{array}{l}x+y\ge 15\\ \\0.65x+0.78y<20\\ \\x\ge 0\\ \\y\ge 0\end{array}\right.[/tex]