Answer:
-15
Step-by-step explanation:
When m=3 and n=-4
So, put the values
7(3)+3(3)(-4)
-> -15
= 7(3) + 3(3)(-4)
= 21 + 3(3×-4)
= 21 + 3(-12)
= 21 + -36
= 21-36
= -15
