Answer:
x = 1 ±2sqrt(5)
Step-by-step explanation:
2x^2-4x-9=29
Add 9 to each each side
2x^2-4x-9+9=29+9
2x^2-4x=38
Divide by 2
2/2x^2-4/2x=38/8
x^2 -2x =19
Complete the square
x^2 -2x + (-2/2)^2 = 19 +(-2/2)^2
x^2 -2x +1 = 19+1
(x-1)^1=2 = 20
Take the square root of each side
sqrt((x-1)^2) = ±sqrt(20)
x-1 = ±sqrt(20)
Add 1 to each side
x-1+1 = 1 ±sqrt(20)
x = 1 ±sqrt(20)
Simplifying the square root of 20
x = 1 ±sqrt(4)sqrt(5)
x = 1 ±2sqrt(5)
We know we have $4.40 for 4. Divide 4.40 by 4, you get 1.10. So it's $1.10 per notebook. Therefore, divide 6.60 by 1.10. You get 6, so you can get six notebooks with $6.60.
Hope this helps!
AC = x, CD = 2x cause of 30° angle. Use pythagoras then
To solve for the coefficient of variation you will need this formula:
CV = (SD/X) x 100
Where: CV = Coefficient of Variance
X = Mean/average
SD = Standard Deviation
To determine which one is more variable, just get the coefficient of both and compare.
AGE SALARY
CV = (6/55) x 100 CV = (4,100/37,000) x 100
= 10.90 = 11.08
Based on the results, salary is more variable because 10.90<11.08.
Miles driven in 8.07 gallons = 241 miles
Miles driven in 1 gallons = (241/8.07) * 1
= 29.86 miles