Answer:
B
Step-by-step explanation:
Given
7 | 3f + 4 | = 91 ← divide both sides by 7
| 3f + 4 | = 13
The absolute value function always returns a positive value, but the expression inside can be positive or negative. Thus there are 2 possible solutions.
Solve 3f + 4 = 13 → 3f = 13 - 4 = 9 ⇒ f = 3
Solve 3f + 4 = - 13 ⇒ 3f = - 13 - 4 = - 17 ⇒ f = - 
As a check
Substitute these values into the left side of the equation and if equal to the right side then they are the solutions.
f = 3 : 7| 9 + 4| = 7| 13| = 7 × 13 = 91 ← True
f = - 
7 | - 17 + 4| = 7| - 13| = 7 × 13 = 91 ← True
Hence the correct solutions are B
Answer:
The first term is:
Step-by-step explanation:
The arithmetic sequence is defined by

where
is the first term
is the common difference
as
the 17th term of an arithmetic sequence is 51.
i.e. 
so

∵
,
, 
∵ 

Therefore, the first term is:
f(x) = x² - 8x + 3
y = x² - 8x + 3
- 3 - 3
y - 3 = x² - 8x + 16
y - 3 + 16 = x² - 8x + 16
y + 13 = x² - 8x + 16
y + 13 = (x - 4)²
- 13 - 13
y = (x - 4)² - 13
f(x) = (x - 4)² - 13
It would be 179,000. You just multiply them together.