Subtract the sum of 9b2+3c2 and 2b2+bc+2c2 from the sum of 2b2−2bc−c2 and c2+2bc−b2.
Question 71
Subtract the sum of 12ab−10b2−18a2 and 9ab+12b2+14a2 from the sum of ab+2b2 and 3b2−a2.