Answer:
1.17-3.99a
Step-by-step explanation:
You can only combine like terms and 1.17 is not a like term to -0.07a and -3.92a
So you can only combine the like terms
Conic section (or simply conic) is a curve obtained as the intersection of the surface of a cone with a plane. The three types of conic section are the hyperbola, the parabola, and the ellipse. The circle is a special case of the ellipse, previously called the fourth type. Planes that pass through the vertex of the cone will intersect the cone in a point, a line or a pair of intersecting lines, called degenerate conics.
Answer:
the middle 50% of most lengths of pregnancies ranges between 255.62 days and 274.38 days
Step-by-step explanation:
Given that :
Mean = 265
standard deviation = 14
The formula for calculating the z score is 
x = μ + σz
At middle of 50% i.e 0.50
The critical value for 
From standard normal table
+ 0.67 or -0.67
So; when z = -0.67
x = μ + σz
x = 265 + 14(-0.67)
x = 265 -9.38
x = 255.62
when z = +0.67
x = μ + σz
x = 265 + 14 (0.67)
x = 265 + 9.38
x = 274.38
the middle 50% of most lengths of pregnancies ranges between 255.62 days and 274.38 days
6/15 and 12/18 are ratios of 2/3