The general equation is that for every red tile, there must be 12 blue ones.
Algebraically this is expressed as b = 12r where r is red and b is blue. Your teacher might like you to express it as y = 12x where y is blue and x is red. The meaning is the same.
For beginners it might be easier to say b = 12r. So if you have 15 reds then r = 15
b = 12 * r
b = 12 * 15
b = 180 blue tiles.
Pi r2
17 divide 2=8.5
Then
8.5•8.5=72.25
Then
3.14•72.25=226.865
Then
226.865 divide by 2 =113.4325m2
Step-by-step explanation:
Answer: the service charge per hour for premium services is $5.5
the service charge per hour for regular services is $3
Step-by-step explanation:
Let x represent the service charge per hour for premium services.
Let y represent the service charge per hour for regular services.
One customer was charged $38 after spending 2 h in premium areas and 9 regular hours. It means that
2x + 9y = 38- - - - - - - - - - - 1
Another customer spent 3 h in premium areas and 6 regular hours and was charged $34.50. It means that
3x + 6y = 34.5- - - - - - - - - - -2
We would eliminate x by multiplying equation 1 by 3 and equation 2 by 2. It becomes
6x + 27y = 114
6x + 12y = 69
Subtracting, it becomes
15y = 45
y = 45/15
y = 3
Substituting y = 3 into equation 1, it becomes
2x + 9 × 3 = 38
2x + 27 = 38
2x = 38 - 27 = 11
x = 11/2 = 5.5
Answer:
18
Step-by-step explanation:
Remark
This is one of those questions that can throw you. The problem is that do you include the original rectangle or not. The way it is written it sounds like you shouldn't
However if you don't the question gives you 2 complex answers. (answers with the sqrt( - 1) in them.
Solution
Let the width = x
Let the length = x + 5
Area of the rectangle: L * w = x * (x + 5)
Area of the smaller squares (there are 2)
Area = 2*s^2
x = s
Area = 2 * x^2
Area of the larger squares = 2 * (x+5)^2
Total Area
x*(x + 5) + 2x^2 + 2(x + 5)^2 = 120 Expand
x^2 + 5x + 2x^2 + 2(x^2 + 10x + 25) = 120 Remove the brackets
x^2 + 5x + 2x^2 + 2x^2 + 20x + 50 = 120 collect the like terms on the left
5x^2 + 25x + 50 = 120 Subtract 120 from both sides.
5x^2 + 25x - 70 = 0 Divide through by 5
x^2 + 5x - 14 = 0 Factor
(x + 7)(x - 2) = 0 x + 7 has no meaning
x - 2 = 0
x = 2
Perimeter
P = 2*w + 2*L
w = 2
L = 2 + 5
L = 7
P = 2*2 + 2 * 7
P = 4 + 14
P = 18
