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
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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: x =6
Step-by-step explanation:
Answer:
5/9
Step-by-step explanation:
5/9 is 0.5 recurring
Answer:
2A/b = h
Step-by-step explanation:
A=1/2bh
Multiply each side by 2
2A = 2 * 1/2 bh
2A = bh
Divide each side by b
2A/b = bh/b
2A/b = h
Hi there!
We can solve for x knowing that the sum of interior angles in a triangle is 180°.
The square at the bottom indicates a right angle, or 90°. Therefore:
180 = 90 + x + (x + 10)
Combine like terms:
180 = 100 + 2x
Subtract 100 from both sides:
180 - 100 = 2x
80 = 2x
Divide both sides by 2:
x = 40.
