Answer:
12.8km/hr
Step-by-step explanation:
Distance = 76.8km
Time = 6 hours
Speed = distance ➗ time
Speed = 76.8km ➗ 6 hours
Speed = 12.8km/hr
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Answer:
1
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)
29.) This is simply interpreting the linear function.
The function:
96+2.1x
a.) The 96 is what you start with from the beginning. So, we know Rachel weighed 96 ounces when she was born.
b.) Again, interpretation. The 2.1 is the slope, or the change in the line. So we know that Rachel gains 2.1 ounces each day.
30.) For this one, you just have to plug 9 into the equation for x.
