Answer:
The second step because she distributed within the parentheses without adding the negative sign to 13
Lets see
a and b are legs
c=hypotnuse
a^2+b^2=c^2
10^2+b^2=10^2
100+b^2=100
minus 100 both sides
b^2=0
b=0
false, if you have a leg legnth 0, then they lines are right on top of each other
no cannot
