What is the length of segment ab? coordinate point a is (4,0) and point b (0,5) hurry

Hi my sisters and brothers can tell me the answer because i don’t understand the question

Write the equation in logarithmic form e^x=403.429

Which statements describe the solutions to the inequality x< -20 check all that apply. there are infinite solutions. each solution is negative. each solution is positive. the solutions are both positive and negative. the solutions contain only integer values. the solutions contain rational number values.