For this case we propose a system of equations:
x: Let the variable representing the quantity of Granny Smith apples
y: Let the variable representing the number of Gala apples
According to the statement we have:
[tex]x + y = 19\\0.25x + 0.30y = 5.10[/tex]
From the first equation we have to:
[tex]x = 19-y[/tex]
replacing in the second equation:
[tex]0.25 (19-y) + 0.30y = 5.10\\4.75-0.25y + 0.30y = 5.10\\4.75 + 0.05y = 5.10\\0.05y = 5.10-4.75\\0.05y = 0.35\\y = \frac {0.35} {0.05}\\y = 7[/tex]
So, Carl bought 7 Gala apples
On the other hand:
[tex]x = 19-7 = 12[/tex]
So, Carl bought 12 Granny Smith apples
Answer:
Carl bought 7 Gala apples and 12 Granny Smith apples
