The triangle depicted in the scale drawing has an actual area of 81 square units. What is the scale factor from the scale drawing to the actual triangle? (Note: Each square on the grid has a length of 1 unit.)
Scale factor:

What is the first step of an indirect proof of a number that is divisible by two

Arefrigeration system at your company uses temperature sensors fixed to read celsius (°c) values, but the system operators in your control room understand only the fahrenheit scale. you have been asked to make a fahrenheit (°f) label for the high temperature alarm, which is set to ring whenever the system temperature rises above –10°c. what fahrenheit value should you write on the label

Asap! i'm not good math and i'm lost.