Change 0.843 to scientific notation

move the decimal point to the right to have 1 real number to the left of the decimal point,

 since you are moving it to the right the exponent would be negative

 so you get 8.43 x 10^-6

logv3(x+2)=1

rewrite in exponential form:

logb(x) = y is equal to b^y =x

b = 3, y = 1

now solve for x:

3^1 = x+2)

x = 3-2

x = 1

see the picture for the graph.