You can't solve this unless you have numbers to substitute or another equation.
Answer:
Chocolate chip dough = $12
Gingerbread cookie dough = $17
Step-by-step explanation:
Since there are two variables in this problem, setting up a system of equations and using the elimination method will help us find the cost for each package of cookie dough. Based on Ryan's sales of 6 packages of chocolate chip and 12 packages of gingerbread for $276, the first equation is:
6c + 12g = 276
Since Shawna sold 8 chocolate chip and 3 gingerbread for a total of $147.00, the second equation is:
8c + 3g = 147
Using the elimination method, we will need to multiply the second equation by a factor of -4 in order to eliminate the variable 'g':
-4(8c + 3g = 147) = -32c - 12g = -588
Add the two equations:
6c + 12g = 276
+ <u> -32c - 12g = -588</u>
-26c = -312 or c = $12
Plug the value of 'c' into the first equation:
6(12) + 12g = 276 or 72 + 12g = 276 or g = $17
93 students play an instrument because you would take 310 (the total amount of students) and multiply it by 0.3 (the thirty percent) and get 93
