Question
A binary operation * is defined on R the set of real numberr by x*y=x-2y for all a ,y e R if (4*q)*8=6 find q
Answers
mathhelper
x*y=x-2y
then (4*q) = 4 - 2q
and then
(4*q)*8 = 4*q - 16
= (4-2q) - 16
= -2q - 12
but this equals 6
-2q - 12 = 6
-2q = 18
q = -9
check
(4*-9)*8 = (4 - 2(-9))*8 = 22*8
= 22-16 = 6
then (4*q) = 4 - 2q
and then
(4*q)*8 = 4*q - 16
= (4-2q) - 16
= -2q - 12
but this equals 6
-2q - 12 = 6
-2q = 18
q = -9
check
(4*-9)*8 = (4 - 2(-9))*8 = 22*8
= 22-16 = 6