There are two ways to work this out: normal variables or using "imaginary" numbers.
Normal variables:
![(7+2i)(3-i)\\(7*3)+[7*(-i)]+(3*2i)+[2i*(-i)]\\21-7i+6i-2i^{2}\\\\21-i-2i^{2}](https://tex.z-dn.net/?f=%20%287%2B2i%29%283-i%29%5C%5C%287%2A3%29%2B%5B7%2A%28-i%29%5D%2B%283%2A2i%29%2B%5B2i%2A%28-i%29%5D%5C%5C21-7i%2B6i-2i%5E%7B2%7D%5C%5C%5C%5C21-i-2i%5E%7B2%7D)
Imaginary numbers:
Using the result from earlier:
Now since
, then the expression becomes:
Answer:
B) $822
Step-by-step explanation:
The total amount of money she spent can be found by adding her expenses:
312 + 287 + 112 + 111
Once added you get the total amount of:
$822
Factors of 12 : 1, 2, 3, 4, 6, 12
Factors of 20: 1, 2, 4, 5, 10, 20
In both lists of factors, 4 is in common. Therefore, the value of K is 4 because it can divide into both 12 and 20 without a remainder. 2 is also another possible value of K.
Answer:
y=-5/3x+13.
Step-by-step explanation:
As a line that is perpendicular to anoher line has a slope that is the negative reciprocal of the line's original slope, we know that the slope of our new line is -5/3. As it passes point (12, -7), we can use the point slope formula which is y-y1=m(x-x1). So plug in, y+7=-5/3(x-12) and that gives us y+7=-5/3x+20 which gives our final answer of y=-5/3x+13.
Answer:
a ≈ 8.9
Step-by-step explanation:
Set up the equation as so:
8a^2 + 2 = 634
First, subtract two from both sides:
8a^2 = 632
Then, divide by 8 to further isolate the variable.
a^2 = 79
To get rid of the squared, you have to take the square root of both sides. The square root of 79 is roughly 8.9. Ergo, a ≈ 8.9
