9514 1404 393
Answer:
16) No
17) (c)
Step-by-step explanation:
For a lot of multiple-choice matrix problems, a simple test is all that is needed to determine the correct answer.
16) The determinant of A is (-2)(-2) -(2)(-3) = 10. So, we expect to see values in the inverse matrix that are 0.2 and 0.3. Alas, they're not there. The matrices are not inverses.
A^-1 = [[-.2, .3][-.2, -.2]]
__
17) The matrices are both 3×3, so their product is possible (eliminates choice D). The upper left term is different among the answer choices, so we can determine the correct one by computing that term only.
BA=C
c11 = (5)(1) +(7)(5) +(3)(-1) = 5 +35 -3 = 37
This matches the third choice (C).
If you use a calculator to compute the full matrix product, it matches choice C in all details.
I honestly think B but I'm not sure
Answer:
14 arcade games and 8 photobooths were purchased
Step-by-step explanation:
x will represent the number of arcade games
y will represent the number of photobooths
We know that 22 total machines were bought which means that x+y=22
We also know that the total was 53600 which means that 2000x+3200y=53600
We can use substitution to solve this
x+y=22
x-22= -y
-x+22=y
Then plug this in for y in the next equation
2000x+3200(-x+22)=53600
Solve this and get x=14
Then plug in x=14 into any equation (I will choose the x+y one because that's easiest to solve)
14+y=22
this means y=8
This means that 14 arcade games and 8 photobooths were purchased
I double checked the math on desmos and it is correct
