1 ) ( a - b ) ^ 2 * ( a + b ) = ( a - b ) * ( a + b ) * ( a - b ) = ( a ^ 2 - b ^ 2 ) * ( a - b ) = a 6 3 - a ^ 2 * b - b ^ 2 * a + b ^ 3 ; 2 ) ( a + 2 * b ) ^ 2 * ( a - 2 * b ) = ( a ^ 2 - 4 * b ^ 2 ) ( a + 2 * b ) = a ^ 3 + 2 *a ^ 2 * b - 4 * b ^ 2 * a - 8 * b ^ 3 ; 3 ) 7 * c * ( 4 * c + 2 ) - ( 7 + c ) ^ 2 - 3 * c * ( 6 * c + 2 ) - ( - 3 + c ) ^ 2 = 28 * c ^ 2 + 14 * c - 49 - 14 * c + c ^ 2 - 18 * c ^ 2 - 6 * c - c ^ 2 + 6 * c - 9 = 9 * c ^ 2 - 49 + c ^ 2 - 6 * c + 6 * c - 9 = 10 * c ^ 2 - 49 - 9 = 10 * c ^ 2 + 58 ; 4 ) 6 * c * ( 9 * c + 2 ) - ( 6 + c ) ^ 2 - 2 * c * ( 3 * c + 2 ) - ( - 2 + c ) ^ 2 = 54 * c ^ 2 + 12 * c - 36 - 12 * c + c ^ 2 - 6 * c ^ 2 - 4 * c - c ^ 2 + 4 * c - 4 = 54 * c ^ 2 - 36 - 6 * c ^ 2 - 4 = 48 * c ^ 2 - 40 .