Answer:
(3.8x10^3)*(9.4x10^-5)= 3.6x10^-1
(4.2x10^7)*(7.4x10^-2)=3.1x10^6
((8.6x10^-6)*(7.1x10^-9))/((4.1x10^-2)*(2.8x10^-7))=5.3x10^-6
((6.9x10^-4)*(7.7x10^-6))/((2.7x10^-2)*(4.7x10^-7))=4.2x10^-1
Explanation:
For the first one reorder the terms into like catagoriesL
(3.8x9.4)(10^3x10^-5) and then multiply out
35.72x10^(3-5)=35.72x10^-2
Rewrite and simplify to 3.6x10^-1
For the second one, same thing
Reorder: (4.2x7.4)(10^7x10^-2)
Multiply: 31.08x10^(7-2)
Rewrite and simplify 3.1x10^6
For the third one,
Reorder the terms on the top and bottom:
((8.6x7.1)*(10^(-6-9))/(4.1x2.8)*(10^(-2-7))
Simplify: (61.06*10^-15)/(11.48x10^-9)
61.06/11.48=5.318 and then to divide out the exponents you will take the top number (-15) and then add it to the opposite sign as the bottom number (-9). So -9 will become a positive 9+(-15)=-6
5.3x10^-6
For the last one, same steps as the one above,
Reorder: ((6.9x7.7)*(10^(-4-6))/((2.7x4.7)*(10^(-2-7))
Simplify: (5.313x10^-9)/(12.69x10^-9)
5.313/12.69=0.418 and the exponents will cancel each other out -9+9=0. However, your answer needs to be in the format, so you multiply by 10^-1 to get 4.2x10^-1