It looks like an incomplete equation.
3 x10 30 x10
Yes, if x10=y.
60 square feet.
One sequence could be -4, x10, -4, x10, ect.. So the sequence will be 10, 6, 60, 56, 560, 556, 5560, ect..
e could either mean x10^ or 2.718. I think in this case it means x10^. THIS ANSWER WILL REQUIRE AN UPDATE.
No, since there's no decimal point, it equals 875 or 8.75 x 10^2
29000000
60 square feet
0x10=10 because your counting 10 0 times
60 equals seconds in a minute
x5 times x10 equals x50. This is because when you multiply variables with the same base, you add their exponents (5 + 10 = 15), resulting in x^(5+10) = x^15.
That depends on who they are and why their answers should matter as opposed to other peoples' answers.