Question

I need help with this ~
1.(6.0×10^-5)×(3.0×10^4)=
A.18×10^20
B.18×10^9
C.1.8×10^20
D.1.8×10^10

2.(5×10^-2)÷(2×10^3)=
A.2.5×10^-5
B.2.5×10^-1
C.25×10^1
D.25×10^2

Answer 1

when multiplying add powers. when dividing, subtract powers. So, you have

(6.0×10^-5)×(3.0×10^4)
= (6.0*3.0)x10^(-5+4)
= 18.0x10^-1
but that is not scientific notation. You have to shift the decimal point so you get

1.8x10^0 = 1.8

I suspect you have garbled the question somehow.

(5×10^-2)÷(2×10^3)
= (5/2)x10^(-2-3)
= 2.5x10^-5

Answer 2

Online, “*” is used to indicate multiplication to avoid confusion with “x” as an unknown.

Online "^" is used to indicate an exponent, e.g., x^2 = x squared.

When multiplying/dividing, exponents are added/subtracted respectively.

(6*10^-5)(3*10^4) = 18*10^-1 = 1.8

Use similar process on 2.