Hey! Nice question u got there☺
t^2+20t+100 can also be written as (t)^2+2×t×10+ (10)^2
formula used-->(a+b)^2=a^2+2ab+b^2
by this formula, (t)^2+2×t×10+ (10)^2=(t+10)^2
It's factors are (t+10)(t+10)
and it is a perfect square trinomial.
HOPE IT HELPED :D
