Answer: -7324218
Step-by-step explanation: This is a geometric series because we can see the sequence is constantly decreasing by multiples of 5.
5 is being multiplied.
Sum of geometric progression formula: [tex]S_{n}=\frac{a(1-r^{n})}{1-r} \\[/tex]
Sn = sum of n terms
a = first term in sequence
r = common ratio/multiple
n = number of terms
Therefore: [tex]S_{10}=\frac{-3(1-5^{10})}{1-5}[/tex] = -7324218
brainliest please :)
