Answer:
(-3, 3)
Step-by-step explanation:
A half-life of the isotope is 15 days and at start its mass is 32 g.
A table:
t: m:
0 32 g
15 16 g
30 8 g
45 4 g
60 2 g
75 1 g
In the first column is used an arithmetic sequence ( a 1 = 0, d = 15 ).
In the second column is used a geometric sequence ( a 1 = 32, r = 1/2 )
ANSWER: C) 36
EXPLANATION: +7 is the sequence
If R is between Q and S then QR+RS=QS
given
QR=x+4
RS=3x-1
and QS=27
x+4+3x-1=27
combine like terms
4x+3=27
minus 3 both sides
4x=24
divide both sides by 4
x=6
sub back
QR=x+4
QR=6+4
QR=10
RS=3x-1
RS=3(6)-1
RS=18-1
RS=17
x=6
QR=10
RS=17