Answer:
x = 2±sqrt(11)
Step-by-step explanation:
x^2 -4x - 7 =0
Add 7 to each side
x^2 -4x -7+7 =0+7
x^2 -4x =7
To complete the square take the coefficient of the x term and divide by 2 and then square it. Add it to both sides
-4 /2 = -2 then square
(-2)^2 = 4
Add 4 to both sides
x^2 -4x+4 =7+4
x^2 -4x+4 = 11
Factor the left side into (x-b/2)^2
(x-2)^2 =11
Take the square root of each side
sqrt((x-2)^2) =±sqrt(11)
x-2 = ±sqrt(11)
Add to to each side
x-2+2 = 2±sqrt(11)
x = 2±sqrt(11)
If 14 out of 20 is correct, then that is : 14/20 = 0.70 = 70%
Here is the answer to your question as This is the way I think it is solved
Answer:
116
Step-by-step explanation:
82 brownies sold for $1 each is $82 in total
140-82=58
each cookie is sold at $0.5 so we need to multiply the rest of the cash by 2
58×2=116
so he needs to sell 116 more cookies to reach his goal
Answer:
Step-by-step explanation:
1/6 x 3/2 = 1/4
Hope it helps