The answer is 6 People. You make the two equations first 12.99x and 8.99x+20. And then make them equal each other 12.99x = 8.99x+20. Then you use algebra to solve for the x and you get an answer of 5. That is the number of people that would cause the two prices to break even (be the same price). So in order for the group rate to be the better deal you need 6 people to attend.
Answer: Todd used 27 black tiles.
Step-by-step explanation:
Let x represent the number of black tiles that Todd used.
Todd uses 21 white tiles & some black tiles to make a mosaic. This means that the total number of white and black tiles that Todd used is 21 + x
Each tile has an area of 3 square centimeters. This means that the total area covered by the white tiles is
21 × 3 = 63 square centimeters
Also, the total area covered by the black tiles is
3 × x = 3x square centimeters
The mosaic has a total area of 144 square centimeters. This means that
3x + 63 = 144
3x = 144 - 63
3x = 81
x = 81/3 = 27
The correct answer should be :
Option 3 : 
Hope this helps,
Davinia.
Answer:
7x+72xy
Step-by-step explanation:
7x+8x(9y)=7x+72xy
Answer:
x=9
Step-by-step explanation:
x = 3^2
x = 3*3
x=9