Answer:
A) (-infinity, -7]U[-2, -1]
B) [-7, -5]
C) [-5, -2]U[-1, infinity)
The numbers that can be expressed in the form of a fraction are called rational numbers. While that numbers that cannot be expressed in the form of a fraction are called irrational numbers.


is an irrational number, it cannot be expressed in the form of a fraction.
Let the width be x.
Length is 8 feet more than width. Length = x + 8
Area = x(x + 8)
width increased by 4, that is, (x + 4)
Length decreased by 5, (x + 8 - 5) = (x + 3)
Area = (x + 4)(x +3)
Area remains the same
x(x + 8) = (x+4)(x +3)
x² + 8x = x(x +3) + 4(x +3)
x² + 8x = x² +3x + 4x +12
x² + 8x = x² +7x +12 Eliminate x² from both sides
8x = 7x + 12
8x - 7x = 12
x = 12
Dimensions of original rectangle : x, x + 8
12, 12 +8 = 12, 20
Original rectangle is 20 feet by 12 feet
This is a more difficult one to explain. Let's start with the line to the right. It has a slope (m) of
= -1 and a y-intercept of +3 (continue the line to see where it crosses the y-axis). So, the equation of that line is: y = -x + 3 when x ≥ 2. This can also be written as y = 3 - x when x ≥ 2. The only option that has that equation is A.
Answer: A
Answer:
Brand X has to mix 8.4 oz of brand A mixed nuts which contain 35% peanuts and 12.6 oz of brand B mixed nuts which contain 25%, to obtain 21 oz. Bags of mixed nuts that contain 29% peanuts.
Step-by-step explanation:
Hi
We define
, wich means Brand A has 1 oz containing 35% peanuts.
, wich means Brand b has 1 oz containing 25% peanuts.
So we can build an equiation system
(1) 
(2)
, after fixing it a little
(2)
As we can use any method to solve the system, I used a calculator wich thrown the following results
and
.