Your friend says "multiplying a number by 5 is a 500% increase" describe and correct the error in your friend's reasoning.

y=3n + 1

step-by-step explanation:

this is wrong because it says the second number is one less and i added one instead

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.