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:
Answer:
80x⁴
Step-by-step explanation:




The fourth term of the expansion has the constant a,
the coefficient of a is 80x⁴
Answer:
184.68cm
Step-by-step explanation:
19x3.6=68.4
68.4x2.7=184.68
I think the answer is C. and you accidentally put the dot in the wrong place.
Range is the value of y
f(x)=-x²+5
when x=-1, f(x)=-(-1)²+5=4
when x=2, f(x)=-(2)²+5=1
so 1<y≤4
the second piece: f(x)=2x-3
when x=2, f(x)=2(2)-3=1
when x=5, f(x)=2(5)-3=7
so 1≤y<7
union of the two parts of y: 1≤y<7
[1,7) is the answer.