Let x be the cost of 1 shirt and y be the cost of 1 scarf.
Since, 3 shirts and 2 scarves cost $94, we have,
3x + 2y = 94
Since the number of unknowns is greater than the number of equations (2 > 1), the above system has infinitely many solutions.
If t is the cost of 1 scarf, then
3x + 2t = 94
3x = 94 - 2t
x =
For different values for t, we will get different values for x.
Set t = 2.
Then, x =
=
=
= 30
So, if the cost of 1 scarf is $2, then the cost of 1 shirt is $30.
Answer:
Step-by-step explanation:
A "critical number" is a function argument where the function has zero or undefined slope. A polynomial function never has undefined slope, so we're looking for the x-values where f'(x) = 0.
A graphing calculator easily shows the points that have zero slope. They are found at x = 3 and x = 6.
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Setting the derivative to zero is another way to find the points with zero slope:
f'(x) = 6x^2 -54x +108 = 6(x^2 -9x +18) = 6(x-3)(x-6)
The derivative will be zero where the factors are zero, at x=3 and x=6.
The critical numbers are x=3 and x=6.
