Hey i want to know how to divide but i only know how to multiply

Afarmer sells 9.5 kilograms of apples and pears at the farmer's market. 4/5 of the weight is the apples and the rest is the pears. how many kilograms of pears did she sell at the farmers market

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

What is the simplified form of (3.25x10^3)(7.8x10^6) written in scientific notation?