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
C I think so sorry if I’m wrong
Answer:
Step-by-step explanation:
The dimensions of the rectangle are represented by functions:
The area is length × width of a rectangle.
Expand brackets and solve.
Answer:
11/4 or 2.75 pints
Step-by-step explanation:
We want to find the difference between the original amount of blueberries and the amount she ate
original amount-amount ate
3 1/2 -3/4
To subtract, we need common denominators
The common denominator of 2 and 4 is 4
3 1/2=7/2
Multiply by 2/2 to get a common denominator of 4
7/2*2/2=14/4
Now, we have common denominators and can subtract
14/4-3/4
Subtract the numerators, and leave the denominators as 4
11/4 =2.75
She has 11/4 or 2.75 pints left
Midpoint=12.5 let me know if this helps
