Answer:
7.8 * 10^7
Explanation:
Group coefficients together and exponents together to multiply numbers in scientific notation.
( 7.8 * 1 ) ( 10 ^3 * 10^4)
Multiply 7.8 times 1.
7.8 * (10^3 * 10^4)
Use the power rule a^m * a^n = a^(m+n) to combine exponents. So, add 3 and 4
7.8 * 10^7