CD is called the middle base and is equal to :(AB + EF)/2
CD = <span>(AB + EF)/2
4x = [(x</span>²+10) + (8-x)]/2
8x = x²+10+8-x
8x= x²-x+18
x²-9x+18 = 0
x' = [-b+√(b²-4.a.c)]/2a & x" = [-b-√(b<span>²-4.a.c)]/2a
x'= 6 and x" = 3, So we have2 values of x</span>
Not sure what simp lies firm is
Answer: 6.4
Step-by-step explanation: If rounding to one decimal place, your answer would be 6.4.
49.6 divided by 7.8 = 6.35897435...
Now, we see that after the 3 (The first decimal place) there is a five. Because we are rounding to the first decimal place the second decimal place will tell us to round up or down. In this case because it's a five, we would round up.
Answer:
x = 5
y = 4
Step-by-step explanation:
multiply the second equation by -1 and add the first equation to eliminate "x"

_____________


Replace "y" in the first equation:




Hope this helps
Answer: 0.0228
Step-by-step explanation:
Given : The mean and the standard deviation of finish times (in minutes) for this event are respectively as :-

If the distribution of finish times is approximately bell-shaped and symmetric, then it must be normally distributed.
Let X be the random variable that represents the finish times for this event.
z score : 

Now, the probability of runners who finish in under 19 minutes by using standard normal distribution table :-

Hence, the approximate proportion of runners who finish in under 19 minutes = 0.0228