In order to find the surface area of a rectangle:
-- Find or measure the length of the rectangle.
-- Find or measure the width of the rectangle.
-- Make sure both quantities are in the same units.
If they're not, then convert one or the other so that they are.
-- Multiply the two numbers.
The product is the area of the rectangle, in units of
square-(the unit in which the dimensions are measured).
A. 8 books on each shelf
B. 4 shelves for mystery, 7 shelves for biography
Step-by-step explanation:
x is -9
hope it helps!:)
Let the equal sides of the isosceles Δ ABC be x.
Given that the perimeter of Δ ABC = 50m.
Therefore, 2x + AC = 50 --- (1)
It is also given that the perimeter of Δ ABD = 40m.
Therefore, x + BD + AD = 40
BD is the median of the Δ ABC. Therefore, D is the midpoint of AC.
So AD = CD.
Or, AD =
AC
Therefore, 
Multiply both sides by 2.
2x + 2BD + AC = 80
From (1), 2x + AC = 50.
Therefore, 2BD + 50 = 80
2BD = 80 - 50
2BD = 30
BD = 15m.
A rate in which the numerator and the denominator are equal to a rate of one