What ratio is used to find the rate of change or slope of a linear function?

Planning for the possibility that your home might get struck by lighting and catch on fire is part of a plan for ?

What is the value of x in the this question ?

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of