A new operation is defined: a ⁃ B = AB + 2a-3b, where a and B are rational numbers, and the value of + {⁃ B} is calculated?

A new operation is defined: a ⁃ B = AB + 2a-3b, where a and B are rational numbers, and the value of + {⁃ B} is calculated?


Can you explain the specific process?



A new operation *: if a and B are rational numbers, then a * b = 2a-3b, please calculate 2 * (- 5) = how much
A math problem of preparatory grade


2*(-5)=2*2-3*(-5)=19



A new operation *: if a and B are rational numbers, then a * b = 3b-2a. Please calculate 2 * (- 5)


-19////