If x = 1! + 2! + 3! + 4! + 5! + …. + 2020!
What is first unit digit of x ?

Step-by-step explanation:

x = 1! + 2! + 3! + 4! + 5! + ... + 2020!

x = 1 + 2 + 6 + 24 + 120 + 720 + ..0 + 0 +.... + ....0

x = 33 + 120 + ...0 + ...0 + .... + ...0

x = ......3

→ So, the first unit digit of x is 3

1010: 3030

is it i think

so the possibilities of the measurement of the side of the triangle are either it is longest side or not the longest side

when it is the longest side

s < 25 + 35s < 60

if it is not the longest side

35 < 25 + s10 < sso 10 < s < 60so the perimeter70 < p < 130