Answer:
or 
Step-by-step explanation:
The given quadratic equation is
Group the constant terms on the right hand side.
Divide through by 5.
Add the square of half the coefficient of x., which is 
to both sides of the equation.
The left hand side is now a perfect square.
Take the square root of both sides;
or 
or 
or
Step-by-step explanation:
Snskqkqnw wkskskwnw wnwnnwnw wkwlwkw w wlsks q wksos w ww wkskskwnw w. Ws sjsjqnqbnwnw qnskskdixixkndnsw q wbqjwjwjwb w wsbwwbwhsuxuuxjxjdjdbwbwbdbdbddbndjsjdjdjsjwjwhwhwhwhwhwbwbs s. S sbsbsbdnsjjd
The probability any one system works is 0.99
So the probability of any one system failing is 1-0.99 = 0.01, so basically a 1% chance of failure for any one system
Multiply out the value 0.01 with itself four times
0.01*0.01*0.01*0.01 = 0.000 000 01
I'm using spaces to make the number more readable
So the probability of all four systems failing is 0.00000001
Subtract this value from 1 to get
1 - 0.00000001 = 0.99999999
The answer is 0.99999999 which is what we'd expect. The probability of at least one of the systems working is very very close to 1 (aka 100%)
4 (k+3) (k+) is the answer
