a) b1=4 q=5
b2=b1×q=4×5=20
b3=b1×q^2=4×5^2=4×25=100
b4=b1×q^3=4×5^3=4×125=500
b) b1=-3 q=2
b2=-3×2=-6
b3=-3×2^2=-3×4=-12
b4=-3×2^3=-3×8=-24
c)b1=25 q=1/4
b2=25×1/4=25/4
b3=25×(1/4)^2=25×1/16=25/16
b4=25×(1/4)^3=25×1/64=25/64
d) b1=-729 q=-1/9
b2=-729×(-1/9)=729/9=81
b3=-729×(-1/9)^2=-729×1/81=-729/81=-9
b4=-729×(-1/9)^3=-729×(-1/729)=1
