The quadratic formula is the result of completing the square for ax^2+bx+c=0 when a,b, and c are unknown values. This result is:
x=(-b±√(b^2-4ac))/(2a), we have x^2-x-2=0 so
x=(1±√(1+8))/2
x=(1±√9)/2
x=(1±3)/2
x=-1 and 2
The time taken to reach train from Zurich to Paris is 8 hours 52 minutes.
Step-by-step explanation:
The given is,
Train leaves Zurich at 22:40
Train arrives Paris at 07:32
Step:1
Time taken to reach from zurich to paris,
= Train leaves at Zurich - Train arrives at Paris
= 22:40 - 07:32
= 8.52 hours
Step:2
Time taken by train to reach from zurich to paris in minutes,
= 8.52 hours
= 4831 minutes 12 secs
Result:
The time taken to reach train from Zurich to Paris is 8 hours 52 minutes, if a train leaves Zurich at 2240 and arrives in Paris at 0732.
Put the equation in standard linear form.
Find the integrating factor.
Multiply both sides by 
.
Now the left side the derivative of a product,
Integrate both sides.
On the right side, integrate by parts.
Solve for 
.
Answer:
x = -6/5
y = -8/5
Step-by-step explanation:
2x + y = -4
Y = 3x + 2
Substitute the second equation into the first equation
2x + 3x+2 = -4
Combine like terms
5x +2 = -4
Subtract 2 from each side
5x+2-2=-4-2
5x = -6
Divide by 5
5x/5 = -6/5
x = -6/5
Now we need to find y
y = 3x+2
y = 3(-6/5)+2
y = -18/5 + 10/5
y = -8/5
It's not the difference of squares, rather it is the square of a difference. That leaves a perfect square trinomial, which narrows your selection to two choices. An expression with 2 terms is not a trinomial, so that further narrows your selection. The appropriate choice is
... (4xy -3z)² = 16x²y² -24xyz +9z², a perfect square trinomial
_____
The expression you have in your problem statement has no z term, so none of the choices is applicable to that one.
