Answer:
$54
Step-by-step explanation:
first find 1/4 of $80 and then take that answer and find 10% of that to get your answer
2/5 of the students is equivalent to 394 students. The total number of students involved is thus 394*5/2.
The matrix represents the system:
-3x+5y=15
2x+3y=-10, which is choice c.
We can see it more clearly from the way we multiply matrices, as follows:
![\[ \left[ {\begin{array}{cc} -3 & 5 \\ \ 2 & 3 \\ \end{array} } \right] \] \cdot \[ \left[ {\begin{array}{c} x \\ y \\ \end{array} } \right] \]= \left[ {\begin{array}{c} -3\cdot x+5\cdot y \\ 2\cdot x+3\cdot y \\ \end{array} } \right] \]= \[ \left[ {\begin{array}{c} 15 \\ -10 \\ \end{array} } \right] \]](https://tex.z-dn.net/?f=%20%5C%5B%0A%20%20%5Cleft%5B%20%7B%5Cbegin%7Barray%7D%7Bcc%7D%0A%20%20%20-3%20%26%205%20%5C%5C%0A%20%20%20%20%5C%202%20%20%26%203%20%5C%5C%0A%20%20%5Cend%7Barray%7D%20%7D%20%5Cright%5D%0A%5C%5D%20%5Ccdot%20%20%5C%5B%0A%20%20%5Cleft%5B%20%7B%5Cbegin%7Barray%7D%7Bc%7D%0A%20%20%20x%20%5C%5C%0A%20%20%20%20y%20%5C%5C%0A%20%20%5Cend%7Barray%7D%20%7D%20%5Cright%5D%0A%5C%5D%3D%20%5Cleft%5B%20%7B%5Cbegin%7Barray%7D%7Bc%7D%0A%20%20%20-3%5Ccdot%20x%2B5%5Ccdot%20y%20%5C%5C%0A%20%20%20%202%5Ccdot%20x%2B3%5Ccdot%20y%20%5C%5C%0A%20%20%5Cend%7Barray%7D%20%7D%20%5Cright%5D%0A%5C%5D%3D%20%5C%5B%20%5Cleft%5B%20%7B%5Cbegin%7Barray%7D%7Bc%7D%2015%20%5C%5C%20-10%20%5C%5C%20%5Cend%7Barray%7D%20%7D%20%5Cright%5D%20%5C%5D)
Answer: C
Answer:
She would have saved 14 dollars more
Step-by-step explanation:
Hope this helps and plz mark brainliest :)
Answer:
Step-by-step explanation:
Represent the length of one side of the base be s and the height by h. Then the volume of the box is V = s^2*h; this is to be maximized.
The constraints are as follows: 2s + h = 114 in. Solving for h, we get 114 - 2s = h.
Substituting 114 - 2s for h in the volume formula, we obtain:
V = s^2*(114 - 2s), or V = 114s^2 - 2s^3, or V = 2*(s^2)(57 - s)
This is to be maximized. To accomplish this, find the first derivative of this formula for V, set the result equal to 0 and solve for s:
dV
----- = 2[(s^2)(-1) + (57 - s)(2s)] = 0 = 2s^2(-1) + 114s - 2s^2
ds
Simplifying this, we get dV/ds = -4s^2 + 114s = 0. Then either s = 28.5 or s = 0.
Then the area of the base is 28.5^2 in^2 and the height is 114 - 2(28.5) = 57 in
and the volume is V = s^2(h) = 46,298.25 in^3
