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*9)+3=7
Step-by-step explanation:
three more is +3
product of a number and 9 is x*9
and equal to seven is =7
6.28 (equation for circle perimeter is 2πr)
Answer: 310 centimeters square of paper
Explanation: to find the answer you need to know the surface area of the box. So you use the formula SA = 2ab+2bc+2ac
A=7
B=10
C=5
After inputting the values you get:
SA = 2(7)(10) + 2(10)(5) + 2(7)(5)
and after simplifying:
SA = 140+100+70
SA=310
Answer:
The answer is: 4,500,000 kilometers or in scientific notation: 4.5 x 10^6 kilometers.
Step-by-step explanation:
Multiply to get the answer:
300,000 * 15 =
4,500,000 km
In scientific notation: 4.5 x 10^6
