Question

if* is an operation such that for any two integers a and b, a*b=a+b+5, then?
a. -7 *-4
b.- 2* - 9​

Answer 1

Answer:

from given information  

a*b = a×b + (a×a + b×b)

so (-7)*(-4) =(-7)+(-4)+5

                   = 28-11+5

                   = 22

    (-7)*(-4) =22

(-2)*(-9)= (-2)+(-9)+5

          = (18) -11 +5

          = 23-11

          = 12

(-2)*(-9) = 12

Step-by-step explanation: