Answer:
It's 21.
Step-by-step explanation:
The factors of 9 are 3 and 3. (You need to multiply 3x3 to get 9.) The factors of 10 are 5 and 2. But, if you multiply 3 by 5, which gives you 15, and multiply the other 3 by 2, which gives you 6, and then add 6 to 15, you get 21.
Answer: 3x^2 + 7x -15
I dunno if u want me to factor it tho
The final answer for this is 4x^2-25y^2.
1.8, Problem 37: A lidless cardboard box is to be made with a volume of 4 m3
. Find the
dimensions of the box that requires the least amount of cardboard.
Solution: If the dimensions of our box are x, y, and z, then we’re seeking to minimize
A(x, y, z) = xy + 2xz + 2yz subject to the constraint that xyz = 4. Our first step is to make
the first function a function of just 2 variables. From xyz = 4, we see z = 4/xy, and if we substitute
this into A(x, y, z), we obtain a new function A(x, y) = xy + 8/y + 8/x. Since we’re optimizing
something, we want to calculate the critical points, which occur when Ax = Ay = 0 or either Ax
or Ay is undefined. If Ax or Ay is undefined, then x = 0 or y = 0, which means xyz = 4 can’t
hold. So, we calculate when Ax = 0 = Ay. Ax = y − 8/x2 = 0 and Ay = x − 8/y2 = 0. From
these, we obtain x
2y = 8 = xy2
. This forces x = y = 2, which forces z = 1. Calculating second
derivatives and applying the second derivative test, we see that (x, y) = (2, 2) is a local minimum
for A(x, y). To show it’s an absolute minimum, first notice that A(x, y) is defined for all choices
of x and y that are positive (if x and y are arbitrarily large, you can still make z REALLY small
so that xyz = 4 still). Therefore, the domain is NOT a closed and bounded region (it’s neither
closed nor bounded), so you can’t apply the Extreme Value Theorem. However, you can salvage
something: observe what happens to A(x, y) as x → 0, as y → 0, as x → ∞, and y → ∞. In each
of these cases, at least one of the variables must go to ∞, meaning that A(x, y) goes to ∞. Thus,
moving away from (2, 2) forces A(x, y) to increase, and so (2, 2) is an absolute minimum for A(x, y).
A. The number of fabric-pattern-color combinations is 4 * 13 * 9 = 468
B. P(1st choice) = no of novels / total books = 3/6 = 1/2
P(2nd choice) = no of remaining novels/ total remaining books = 2/5
P(both novels) = 1/2 * 2/5 = 1/5 (without replacement assumed)
C. P(1st choice) = no of biographies / total books = 2/6 = 1/3
P(2nd choice) = no of remaining biographies/ total remaining books = 1/5
P(both biographies) = 1/3 * 1/5 = 1/15 (without replacement assumed)
D. P(1st choice) = no of history books / total books = 1/6
P(2nd choice) = no of novels/ total remaining books = 3/5
P(a history, then a novel) = 1/6 * 3/5 = 1/10 (without replacement assumed)
