Step-by-step explanation:
Bringing like terms on one side
a2 - 2 = - 8a + 7a
a2 - 2 = - a
a2 + a - 2
a2 +2a - a - 2
a(a + 2) - 1 (a + 2)
(a + 2) and (a - 1)are the factors
Answer:
OPTION B: K = 15
Step-by-step explanation:
The given equation is: 21 + 3x = 3x + K
Substitute K = 3x
we get: 21 = 3x + 3x + 3x
⇒ 21 + 3x = 6x
⇒ 21 = 3x
This gives the value of x = 7. That means K = 3x gives us a solution. So, OPTION A is eliminated.
Now, K = 15
The equation becomes 21 + 3x = 3x + 15
Subtracting 3x on both the sides, we get:
⇒ 21 + 3x - 3x = 15 + 3x - 3x
⇒ 21 = 15 which can not be correct. So, K = 15 renders the equation meaningless and hence with no solution.
So, OPTION B is the answer.
Note that K = 21 will give the equation with infinitely many solutions.
Probability of finding no defective bulb
=95/100*94/99....86/91
=95!/(85!) / (100!/90!)
= 110983/190120
=>
Probability of finding at least one defective bulb
=1-110983/190120
= 79137/190120
= 0.41625 (to 5 decimal places)
