D. 1.99(x-4) + 11.96
Because you can figure out the total cost of the four costing $2.99 (11.96), that has to be added to the other half of the equation. Simply multiplying 1.99 by x would include all apps instead of just the remaining (x-4).
If she downloaded x total applications, which of the following equations can be used to find how much Sam spent on cell phone application downloads?
A: y = 11.96(x - 4) + 1.99
B: y = 1.99x + 11.96
C: y = 11.96x + 1.99
D: y = 1.99(x - 4) + 11.96
Because you can figure out the total cost of the four costing $2.99 (11.96), that has to be added to the other half of the equation. Simply multiplying 1.99 by x would include all apps instead of just the remaining (x-4).
so ..
y =1.99x + 4
that would be the simplest equation,
Too bad they don't have it
The cost of the four applications that cost $2.99 each can be calculated by multiplying the cost per application ($2.99) by the number of applications (4). This gives us 4 * 2.99 = $11.96.
The cost of the remaining applications that cost $1.99 each can be calculated by multiplying the cost per application ($1.99) by the number of remaining applications (x - 4). This gives us (x - 4) * 1.99.
To find the total amount that Sam spent on cell phone application downloads (y), we need to add the cost of the four applications that cost $2.99 each to the cost of the remaining applications that cost $1.99 each. This gives us the equation y = 11.96 + (x - 4) * 1.99.
Therefore, the correct equation is D: y = 1.99(x - 4) + 11.96.