Step-by-step explanation:
in a geometric sequence there is a constant factor x that is multiplied with every previous term to create the next one.
a2 = 20
a5 = 1280 = a2×x×x×x = a2×x³ = 20x³
64 = x³
x = 4
=> a1 = 5
therefore
an = an-1×4 =

n > 1
1.3/8 because there is a total of 8 marbles but only 3 of them are green.
2. A 52 deck of cards has 4 or each card not including the Jokers so it would be 4/52.
3.30 red 90 total 30/20
4. all you have to do is 4*3=12
5. 4 of each card 2 red 2 black 2 red jacks 52 cards 2/52.
6.&7. coins aren't my cup of tea all i can say is maybe google it :P
8.2 pairs of blue socks 10 total pairs 2/10 or 1/5
sorry about 6 and 7 but i still hope this helped you
1.)-3y=2* -3-9
-3y=-6-9
-3y=-15
y=5
-3*5=-15
2.)-3y=2*0-9
-3y=0-9
-3y=-9
y=3
-3*3=-9
3.)-3y=2*3-9
-3y=6-9
-3y=-3
y=1
-3*1=-3
1. 7x(x + 3)
7x(x) + 7(3)
7x² + 21
2. (7x + 1)(x + 3)
7x² + 21x + x + 3
7x² + 22x + 3
3. (x² + x)²
(x² + x)(x² + x)
x^4 + x³ + x³ + x²
x^4 + 2x³ + x²
-6x-4(-7x-13)=-58
Multiply the bracket by -4
-6x-4(-7)-4(-13)= -58
-6x+28x+52= -58
22x+52= -58
Move +52 to the other side. Sign changes from +52 to -52.
22x+52-52= -58-52
22x= -110
Divide by 22.
22/22x= -110/22
x= -5
Answer: x= -5