Question

7×10⁷+2·10⁸ =
4,5×10⁵-3× 10⁴=
(2,25 ×10⁴): (1,5×10⁶)=
(1,2×10³) ×(6×10²) =​

Answer 1

=27*10^7
=420000
=1,5*10^-2
=7,2*10^5