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Have fun and feel free to ask me something new.
Or we can prove some properities without calculating by details
Answer:
1. 15
2. 8
Step-by-step explanation:
The two sequence are geometric progression GP, because they follow a constant multiple (common ratio)
The nth term of a GP is;
Tn = ar^(n-1)
Where;
a = first term
r = common ratio
For the first sequence;
The common ratio r is
r = T3/T2 = 540/90 = 6
r = 6
T2 = ar^(2-1) = ar
T2 = 90 = ar
Substituting the values of r;
90 = a × 6
a = 90/6
a = 15
First term = 15
2. The sam method applies here.
Common ratio r = T3/T2 = 128/32 = 4
r = 4
T2 = ar^(2-1) = ar
T2 = 32 = ar
Substituting the values of r;
32 = a × 4
a = 32/4
a = 8
First term = 8
Step-by-step explanation:
since y=6x
by substitution
-5x+ 2 (6x)= -42
-5x+ 12x=-42
7x= - 42
divide both sides by 7
x= 6
y=6x
y =6*6
y=36
Answer:
2 minutes, 40 seconds
Step-by-step explanation:
set up a proportion and cross-multiply:
4/3 = x/2
3x = 8
x = 2 2/3 which is 2 minutes, 40 seconds
