What is the length of the equal sides of an isosceles right triangle with hypotenuse 20cm?

Keisha makes a large sandwich for a family picnic she takes 1/2 of them the sandwich to the picnic her family eats 3/8 of the whole sandwich what fraction of the whole sandwich does keisha bring back from the picnic

Which expression is equivalent to (3^2)^-2 a.-81 b.-12 c.1/81 d.1/12

Which of these tables represents a non-linear function?