Jamesaiden

3,   -6,   12,   4,   20

  -9   +18   -8   +16

you can see the pattern from here.

so, 20 - 7 = 13

r = ratio

a2 = a1*r

a3 = a1*(r^2)

a4 = a1*(r^3)

a5 = a1*(r^4)

a2/a4 = a1*r/a1*(r^3)=1/r^2

1/r^2 = 3

r*2 = 1/3

a5/a3 = a1*(r^4)/a1*(r^2) = r^2 = 1/3

= $\frac{7\times 10^{23}}{100}$

= $7\times 10^{21}$

4/6*150 = 100

$6\times 14\times 12=1008$

$(1-\frac{50}{100})\times 1008=\frac{1}{2}\times 1008=504$

y = -2x + 20

6x - 5y = 12

6x - 5(-2x + 20) = 12

6x + 10x - 100 = 12

16x = 112

x = 7

y = -2x + 20​

y = -2*7 + 20

y = 6

1 + 2 + 3 + ... + 8 = 36

factor of 36 between 1 and 10 : 2, 3, 4, 6, 9

total : 5

Here is the picture

$\angle A=\angle B=\angle C=60^\circ$

tringangle ABC is an equilateral triangle because AC, AB, BC are all radius, so the length is same

The length of the common chord :

$2\times \sqrt{10^2-5^2}=2\times 5\sqrt{3}=10\sqrt{3}$

$\frac{12}{100}\times 125=\frac{12}{4}\times 5=3\times 5=15$

t(-4) = -3 - 2*(-4) = -3 + 8 = 5

t(5) = -3 - 2*5 = -3 - 10 = -13

= $\frac{1}{3}\times \pi \times (16-12)$

= $\frac{4}{3}\pi$

length of edges a cube : 156/12 = 13

volume = 13^3 = 2197