Answer:20 months
Step-by-step explanation:
2% of 1000 is 20 1000-1400=400
400/20=20 so 20 months
To find 4/5 of 20.5 the first step is to convert 4/5 into a decimal. You can do that by dividing 4 by 5.
4/5 is .8 so your equation would now be .8 of 20.5
"of" states that you are multiplying, so .8 times 20.5 is 16.4
4/5 of 20.5 is 16.4
It's 
which gives 5.23 times increase in 10 years, so 523% of oryginal price
Answer:
Either, (9+√69)/6 or (9-√69)/6
Step wise:
3x²-9x+1=0-------------------(i)
comparing equation onw with (ax²+bx+c=0), we get,
a=3, b=-9, c=1
now,
using Quadratic Formula,
(-b±√b²-4ac)/2a=x
{-(-9)±√(-9)²-4.3.1}/2.3=x
(9±√81-12)/6=x
(9±√69)/6=x
Taking +(ve) sign Taking -(ve) sign
(9+√69)/6=0 (9-√69)/6=0
∴(9+√69)/6=0 ∴(9-√69)/6=0
[∵They cannot be further solved]
X = pencils, y = pens
8x + 6y = 8.50
4x + 4y = 5.....multiply by -2
----------------
8x + 6y = 8.50
-8x - 8y = -10 (result of multiplying by -2)
-----------------add
-2y = - 1.50
y = -1.50 / -2
y = 0.75 <=== pens cost 0.75
4x + 4y = 5
4x + 4(0.75) = 5
4x + 3 = 5
4x = 5 - 3
4x = 2
x = 2/4
x = 0.50 <== pencils cost 0.50
