Answer:
<em>b. 5 + 17i</em>
Step-by-step explanation:
Subtracting the second equation by 18 on both sides, we have xy=-18. Next, we divide both sides by x to get y=-18/x Plugging that into the first equation, we have x+2(-18/x)=9. Multiplying both sides by x, we get x^2-36=9x. After that, we subtract both sides by 9x to get x^2-9x-36=0. Finding 2 numbers that add up to -9 but multiply to -36, we do a bit of guess and check to find the answers to be -12 and 3. Factoring it, we get
x^2-12x+3x-36=x(x-12)+3(x-12)=(x+3)(x-12). To find the x values, we have to find out when 0=(x+3)(x-12). This is simple as when you multiply 0 with anything, it is 0. Therefore, x=-3 and 12. Plugging those into x=-18/y, we get x=-18/y and by multiplying y to both sides, we get xy=-18 and then we can divide both sides by x to get -18/x=y. Plugging -3 in, we get -18/-3=6 and by plugging 12 in we get -18/12=-1.5. Therefore, our points are (-3,6) and (12, -1.5)
Answer:
x=29 CEF=103 BEF=58
Step-by-step explanation:
161=3x+16+2x
5x=145
x=29
Answer:
X= -1 or X= -3 . Probably the first one
Step-by-step explanation:
You must first normalize this in order to use a Z-score table. To convert what you have into a Z score you must use this formula: (x- mean) /standard deviation. In your case (334-310)/12=2. So now you want the probability that a score is greater than 334, which in turn means you want P(Z>2)=1-P(Z<2)=1-.9772=0.0228=2.28%.
