The explicit formula for arithmetic sequence is:
an=a+(n-1)d
where:
a=first term
d=common difference
given:
a3=22
a(17)=-20
substituting this in our equation we get:
22=a+(3-1)d
22=a+2d
a=22-2d........i
also:
-20=a+(17-1)d
-20=a+16d.....ii
but substituting i in ii we get:
-20=22-2d+16d
-20-22=14d
-42=14d
d=-3
but:
a=22-2d
a=22-2(-3)
a=28
thus the formula will be:
an=28-3(n-1)
thus the first term will be 28
the 2nd term will be:
a2=28-3(2-1)
a2=25
the 3rd term will be:
a3=28-3(3-1)
a3=28-6
a3=22
a4=28-3(4-1)
a4=28-9
a4=15
a5=28-3(5-1)
a5=28-3(4)
a5=28-12
a5=15
Answer:
3/10
Step-by-step explanation:
7+3= 10 so 7+3=10/10 which is one mile
The given quadratic expression; 5b² -6b -2 is prime because the discriminant is not a perfect square.
<h3>
What is the discriminant of the expression?</h3>
According to the task content; it is required to identify if the expression is prime.
On this note, it follows that the discriminant of the expression can be evaluated as follows;
= 36 -(4× 5 × -2)
= 76.
Hence, the expression is prime since 76 is not a perfect square.
Read more on discriminant;
brainly.com/question/2507588
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