In an arithmetic sequence, if a2= 5 and a10= 19 find a6
1 answer:
Answer:
a₆ = 12
Step-by-step explanation:
The nth term of an arithmetic sequence is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₂ = 5 and a₁₀ = 19 , then
a₁ + d = 5 → (1)
a₁ + 9d = 19 → (2)
Subtract (1) from (2) term by term to eliminate a₁
8d = 14 ( divide both sides by 8 )
d = 1.75
Substitute d = 1.75 into (1)
a₁ + 1.75 = 5 ( subtract 1.75 from both sides )
a₁ = 3.25
Then
a₆ = 3.25 + 5(1.75) = 3.25 + 8.75 = 12
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Answer:
x =4 ,y =4 and z =0 is the solution.
Step-by-step explanation:
We shall solve the equations using elimination method
In equation 2 and 3 we can see that coefficient of z in both equations are same with opposite sides , adding equations (2) and (3)
3y+5z = 12
y -5z = 4 adding the equations
___________
4y = 16
dividing both sides by 4
y =
y = 4
Plugging the value of y in equation 2 or equation 3 ,we get
3(4) +5z = 12
12+5z = 12
5z = 12-12 or 5z =0 gives z =0
plugging y =4 and z =0 in equation 1
2x+3(4)+ 0 = 20
2x+12 = 20
2x =20-12
2x = 8
x = 8 divided by 2 gives
x =4
therefore solution of the system is given by
x=4 , y =4 and z =0