The scale is evenly balanced. Explain how to find the weight (w) of one turtle. 

8 units

Step-by-step explanation:

Set this up as an equation with a variable for turtles. Count up the other side of the scale (without turtles). Add up the three 1s and the 4 to get 7. Then add up all four 7s. This will get you with an equation 3t+4=28.

To solve this, first subtract 4 from both sides to get 3t=24. Now divide both sides by 3. 24/3=8. Each turtle weighs 8 units.

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.