how do you solve this? 5 √6 ( 4 - √10 )

What is the missing reason in step 5? linear pair postulategivendefinition of complementary anglescongruent complements theorem

At 6 1/2 cents per pound of string beans how much does 7 pounds cost

If 30 lb of rice and 30 lb of potatoes cost ? $27.60? , and 20 lb of rice and 12 lb of potatoes cost ? $15.04? , how much will 10 lb of rice and 50 lb of potatoes? cost?