If you increase the price 9 times which is 5 dollars more each time you get only 30 students that are willing to buy it. Any more increases will lead to no one wanting to buy it.
You have two binomials. I would just FOIL them:
First: 4 x 2 = 8
Outside: 4 (-√3) = -4√3
Inside: -3√3 (2) = -6√3
Last: -3√3 (-√3) = 9
Addummup: 8 - 4√3 - -6√3 + 9 = 17 - 10√3
Answer:
its d
Step-by-step explanation:
you set it up like a fraction then you cross multiply then divide which is 6 then you add 8+6=14
x 75
--- -----
8 100
Answer:
centre = (2, - 1), radius = 6
Step-by-step explanation:
Rearrange the equation by placing the x and y terms together and adding 31 to both sides
Given
x² + y² - 4x + 2y - 31 = 0, then
x² - 4x + y² + 2y = 31
Use the method of completing the square
add ( half the coefficient of the x/y term )² to both sides
x² + 2(- 2)x + 4 + y² + 2(1)y + 1 = 31 + 4 + 1
(x - 2)² + (y + 1)² = 36
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r the radius
compare to (x - 2)² + (y + 1)² = 36, then
centre = (2, - 1) and r = 
= 6
She saves 10 per week.......after 4 weeks, she had 90
so if she started with nothing, after 4 weeks she would have 40.....but for her to have 90, she would have had to have started with (90 - 40) = 50.
Think about it....she starts with 50....and then saves 10 for 4 weeks giving her 40......and now she has 40 + 50 = 90
so ur answer is : Roberta had $ 50 before she started to save money each week
