Answer:
x = 2 ± (i)√5 (Answer b)
Step-by-step explanation:
x²-4x+9=0 can be solved in a variety of ways; the first two that come to mind that are also appropriate are (1) completing the square and (2) using the quadratic formula.
Completing the square is fast here:
Rewrite x²-4x+9=0 as x²-4x +9=0
Identify the coefficient of the x term: it is -4
Take half of that, obtaining -2
Square this result, obtaining 4
Add 4 to x²-4x +9=0, in the blank space in the middle, and then subtract 4: x²-4x +4 -4 +9=0
Rewrite x²-4x +4 as the square of a binomial:
(x - 2)² - 4 + 9 = 0 → (x - 2)² = -5
Take the square root of both sides: x - 2 = ±√(-5) = ± (i)√5
Then x = 2 ± (i)√5
69% can be written as
69/100
That cannot be reduced any further since 69 and 100 do not have any common factors other than 1
12 men : 8 hours : 10 days
// Find if every man works 1 hour
12 x 8 men : 1 hour : 10 days
96 men : 1 hour : 10 days
//Find if every man works 15 hours
96 ÷ 15 men : 15 hours : 10 days
6.4 men : 15 hours : 10 days
//Find if every man works 1 day
6.4 x 10 men : 15 hours : 1 day
64 men : 15 hours : 1 day
//Find if every man works 8 days
64 ÷ 8 men : 15 hours : 8 days
8 men : 15 hours : 8 days
Answer: 8 men is needed
Answer : The amount of margarine needed is 1 kg.
Step-by-step explanation :
First we have to convert volume of syrup from mL to L.
Conversion used:
1 L = 1000 mL
or, 1 mL = 0.001 L
So, 225 mL = 0.225 L
Now we have to calculate the amount of margarine needed.
As, 0.225 L of syrup needed 150 g of margarine
So, 1.8 L of syrup needed 
of margarine
Amount of margarine needed = 1000 g = 1 kg (1 kg = 1000 g)
Therefore, the amount of margarine needed is 1 kg.
