Answer:
a = 2 , r = 5
Step-by-step explanation:
The n th term of a geometric progression is
= a
where a is the first term and r the common ratio
Given the 4 th term is 250, then
ar³ = 250 → (1)
Given the 7 th term is 31250, then
a = 31250 → (2)
Dividing the 2 equations gives
= , that is
r³ = 125 ← take the cube root of both sides
r = = 5
Substitute r = 5 into (1)
a × 5³ = 250, that is
125a = 250 ( divide both sides by 125 )
a = 2
Answer:
For x-2y=15, it's x= 15 + 2y. For 2x+4y=-18, it's x= -9-2y.
Step-by-step explanation:
Answer:
1 = -40 2= (-3)(40)/(6) 3=
i am not sure about the answer for question one but i am sure about question 2