B is your answer to this question
Answer:
k can either be
12
or
−
12
.
Step-by-step explanation:
Consider the equation
0=x2+4x+4
. We can solve this by factoring as a perfect square trinomial, so
0=(x+2)2→x=−2 and−2
. Hence, there will be two identical solutions.
The discriminant of the quadratic equation (b2−4ac) can be used to determine the number and the type of solutions. Since a quadratic equations roots are in fact its x intercepts, and a perfect square trinomial will have
2 equal, or 1
distinct solution, the vertex lies on the x axis. We can set the discriminant to 0 and solve:
k2−(4×1×36)=0
k2−144=0
(k+12)(k−12)=0
k=±12
Answer:
The number of ways Tony and Maria can both be selected for the committee is 8 ways.
Step-by-step explanation:
i) Tony and Maria have to be on the committee together or not at all.
ii) Let us consider Tony and Maria as combined as one person.
Therefore now we can say that the number of eligible people for the committee = 9 - 1 = 8.
iii) therefore the number of ways that both Tony and Maria can be selected for the committee are
= 8C1 =
Let x be this number 10% of the number x is (10%)(x) → 0.1x
Then 10% of a number x, added to that number is (1.1x):
x + 0.1x = x(1+0.1) = x(1.1) = 1.1x