In an arithmetic sequence:
Tn=t₁+(n-1)d
t₄=t₁+(4-1)d=t₁+3d
t₅=t₁+(5-1)d=t₁+4d
t₆=t₁+(6-1)d=t₁+5d
t₄+t₅+t₆=(t₁+3d) +(t₁+4d)+(t₁+5d)=3t₁+12d
Therefore:
3t₁+12d=300 (1)
t₁₅=t₁+(15-1)d=t₁+14d
t₁₆=t₁+(16-1)d=t₁+15d
t₁₇=t₁+(17-1)d=t₁+16d
t₁₅+t₁₆+t₁₇=(t₁+14d)+(t₁+15d)+(t₁+16d)=3t₁+45d
Therefore:
3t₁+45d=201 (2)
With the equations (1) and (2) we make an system of equations:
3t₁+12d=300
3t₁+45d=201
we can solve this system of equations by reduction method.
3t₁+12d=300
-(3t₁+45d=201)
-----------------------------
-33d=99 ⇒d=99/-33=-3
3t₁+12d=300
3t₁+12(-3)=300
3t₁-36=300
3t₁=300+36
3t₁=336
t₁=336/3
t₁=112
Threfore:
Tn=112+(n-1)(-3)
Tn=112-3n+3
Tn=115-3n
Now, we calculate T₁₈:
T₁₈=115-3(18)=115-54=61
Answer: T₁₈=61
42 arrived late
You add 127 and 68 to get 195 then you subtract 237 to get 47.
Answer:
Area=153 cm²
Step-by-step explanation:
Length × Width= Area
17×9=153
Answer:
Step-by-step explanation:
In order to find the center and the radius of this circle, you have to complete the square on it. And only for the x-terms, because the y term is squared and there is no other y term. We'll get to that in a second.
Take half the linear x-term, square it and add it to both sides. Our linear term is 10. Half of 10 is 5, and 5 squared is 25. We add 25 to both sides:
The reason we do this is to create a perfect square binomial inside that set of parenthesis. Simplifying the right side as well gives us:
This tells us that the center is (-5, 0). Remember when I said we would get back to the y terms? Because there was only a y-squared and no other y terms, that is the same as writing the equation as
The radius is the square root of the constant. So the radius is 6.
D is the graph you want.
