Answer:
Step-by-step explanation:
We need a system of equations to help us solve this. One of the equations in the system is about the number of cultures bought, and the other one is about the money spent on the cultures. They are 2 very different things!
The #'s equation says that the number of cultures (c) plus the number of vials (v) totaled 57. The equation that puts that together is
c + v = 57
Now for the money part. Each culture costs $8, so the expression for that is 8c; each vial costs $1, so the expression for that is 1v; we know the amount of money spent in total was $106. The equation for that is
8c + 1v = 106
There's our system. 2 unknowns need 2 equations. Go back to the first one and solve it for either c or v. I'll solve for c, just because:
c = 57 - v. Now sub that value for c into the money equation:
8(57 - v) + v = 106 and
456 - 8v + v = 106 and
-7v = -350 so
v = 50. There are 50 vials of fruit flies. To find c, plug that into the first equation:
c + 50 = 57 so
c = 7.
