Shown here are the three essential steps in a proof of the pythagorean theorem which statement is justified in step 1
a 4 (ab)/2= c squared
b b(a + b)= b squared + 2(1/2ba)
c a squared + b squared = c squared
d (a+b)squared = a squared + 2ab + b squared

Simplify the expression. -2/5(10+15m-20n)

Choose the more precise measurement. 26.4 cm or 8.39 cm

Abicycle training wheel has a radius of 3 inches. the bicycle wheel has a radius of 10 inches. approximately how much smaller, in square inches and rounded to the nearest hundredth, is the area of the training wheel than the area of the regular wheel? *