Answer:
=−3
Step-by-step explanation:
=17a+−37−121a+17
=21(a−3)7(−a+3)
=−3
Answer:
Volume: 41.643
Surface area: 119.04 (nearest tenth... I don't know...sorry)
Step-by-step explanation:
I didn't know if you need volume or surface area so you got both!
An= mth term.
an=a₁+(n-1)*d
a₁₂=41
a₁₅=140
a₁₂=41
41=a₁+(12-1)*d
41=a₁+11d
a₁+11d=41 (1)
a₁₅=140
140=a₁+(15-1)*d
140=a₁+14d
a₁+14d=140 (2)
With the equiations (1) and (2) build a system of equations
a₁+11d=41
a₁+14d=140
we solve it.
-(a₁+11d=41)
a₁+14d=140
--------------------
3d=99 ⇒d=99/3=33
a₁+11d=41
a₁+(11*33)=41
a₁+363=41
a₁=41-363=-322
an=a₁+(n-1)*d
an=-322+(n-1)*33
an=-322+33n-33
an=-355+33n
an=-355+33n
To check:
a₁₂=-355+33*12=-355+396=41
a₁₅=-355+33*15=-355+495=140.
Answer:
1/8 cm = 0.125 cm = 1.25 mm
6 * (1.25 mm)^2 = 9.375 mm^2
