Use the properties of exponents to simplify the expression

Question and answers in picture

Pelle's sister is three years older than pelle the father is 5 times as old as pelle the mother was 28 when the sister was born altogether they are 98 years old how old is pelle?

In δabc, if the length of side b is 3 centimeters and the measures of ∠b and ∠c are 45° and 60°, respectively, what is the length of side c to two decimal places?

Jenisey has $24 to spend on seven pencils. after buying them she had $10. how much did each pencil cost.?