x = -3 , y = 6 , z = -4
Take Given equation :
⇒-15 + (-x) + y = 0
substitute values of x and y
⇒-15 + [- ( -3)] + 6
⇒-15 + (3) + 6
⇒-15 + 9
⇒-6
Hence, value of -15 + (-x) + y = - 6
