Answer:

Step-by-step explanation:
we have

we know that
The formula to solve a quadratic equation of the form
is equal to
in this problem we have
so
substitute in the formula

therefore
StartFraction 19 minus StartRoot 365 EndRoot Over 2 EndFraction comma StartFraction 19 + StartRoot 365 EndRoot Over 2 EndFraction
Common ratio, r = (-125)/625 = -0.2
First term, a = 625
7 term
= ar^6
= 625(-0.2)^6
= -0.04
Cross multiplication
or multiplying by a number which goes in both rates
100/100 x 85/100x 23/100=