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:
119
Step-by-step explanation:
because if u see <EAC AND<BAD. are vertical so if u add 62°to 57° or adds up to 119
The probability that the first two electric toothbrushes sold are defective is 0.016.
The probability of an event, say E occurring is:

Here,
n (E) = favorable outcomes
N = total number of outcomes
Let X = the number of defective electric toothbrushes sold.
The number of electric toothbrushes that were delivered to a store is n = 20.
The number of defective electric toothbrushes is x = 3.
The number of ways to select two toothbrushes to sell from the 20 toothbrushes is:


The number of ways to select two defective toothbrushes to sell from the 3 defective toothbrushes is:


Compute the probability that the first two electric toothbrushes sold are defective as follows:
P (Selling 2 defective toothbrushes) = Favorable outcomes ÷ Total no. of outcomes

Thus, the probability that the first two electric toothbrushes sold are defective is 0.016.
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Answer:
3.9 miles
Step-by-step explanation:
Use phytagoras theorem
c²=a²+b²
4²=1²+b²
16=1+b²
b²=16-1
b²=15
b=

b= 3.872
≈3.9miles