If # is a new symbol, let x # y = XY + X + y, then 2 # M = - m in 16

If # is a new symbol, let x # y = XY + X + y, then 2 # M = - m in 16

－6

If * is a new operation symbol, then x * y = 2x-y, then the value of K in (- 1) * y = 4 is

(-1)*y=4
2×(-1)-y=4
-2-y=4
y=-6

Triangle represents a kind of operation symbol. Its meaning is that a triangle B equals 5A + A * B. find the value of X in 2 triangle x equals 28
Triangle represents a kind of operation symbol, its meaning is a triangle B equals 5A + A * B. find the value of X in 2 triangle x equals 28, what is the operation symbol of the triangle (detailed process)

2△x=28
That is, 5 * 2 + 2 * x = 28
10+2x=28
x=9