The total area of pool and border = 361 square feet.
Length of square pool = x
Length of square pool plus border = (x + 1 +1 ) = x + 2
There is 1 foot length on each side on the x length.
The other length of the square pool and border = (x + 2)
Area = (x+2)(x+2)
(x + 2)(x +2) = 361. Let A = x +2
A*A = 361
A² = 361 Take square root of both sides
A = √361
A = 19
A = x + 2 = 19
x = 19 - 2
x = 17
Area of square pool = x*x = 17*17 = 289
Area of the pool = 289 square feet.
Answer:
Step-by-step explanation:
1). 10 = 
10(7 + x) = 1 + 7x
70 + 10x = 7x + 1
10x - 7x = 1 - 70
3x = -69
x = -23
2). 0.2 = 
0.2(12 + x) = 6 + 2x
2.4 + 0.2x = 6 + 2x
2.4 - 6 = 2x - 0.2x
1.8x = -3.6
x = -2
3). 0.8 = 
0.8(x + 0.5) = x
0.8x + 0.4 = x
x - 0.8x = 0.4
0.2x = 0.4
x = 2
4). 3.5 = 
3.5(0.5 - x) = 4 + 2x
1.75 - 3.5x = 4 + 2x
-3.5x - 2x = 4 - 1.75
-5.5x = 2.25
x = -
x = -
Invert the divisor and then multiply 7/9 by your result:
7 -7 -49
--- * ------ = ---------
9 11 99
First let as solve all unit pirce
whistles 21.25 / 25 = $ 0.85 per unit
36 / 50 = $ 0.72 per unit
60 / 80 = $ 0.75 per unit
kazoos
10 / 25 = $ 0.4 per unit
18.50 / 50 = $ 0.37 per unit
27.20 / 80 = $ 0.34 per unit
a.) $ 0.85 - $ 0.72 = $ 0.13
b.) 10 / 25 = $ 0.4 per unit
c.) he must order 80 kazoos she should order