9*23=207
3*39=117
117+207=324
324-28=296
I would first convert the mixed fraction into an improper fraction. To put it lightly, the reciprocal is the numerator and denominator are switched. For this instance it would be 4/37.
3x^2 + 9x + 6 = 0
3x^2 + 3x + 6x + 6 = 0
3x(x + 1) + 6(x + 1) = 0
(3x + 6)(x + 1) = 0
3x + 6 = 0 and x + 1 = 0
3x = -6 and x = -1
x = -2 and x = -1
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
Bob need to paint 205 square feet.
Solution:
Length of the door = 7 ft
Breadth of the door = 5 ft
Area of the door = length × breadth
= 7 × 5
= 35
Area of the door = 35 ft²
The given image is a trapezoid.
Top base = 12 ft
Bottom base = 20 ft
Area of the trapezoid = 


= 240
Area of the trapezoid = 240 ft²
Surface area to paint = Area of the trapezoid – Area of the door
= 240 ft² – 35 ft²
= 205 ft²
Hence Bob need to paint 205 square feet.