18 shells because since Mary has 6 and Tina has 3 shells all you have to do is multiply 6 and 3 to get 18
Answer:
k= -9
Step-by-step explanation:
2k-3=9k+63-3 [expand the 9(k+7) first]
2k-9k=63-3+3 [put the like terms together]
-7k=63 [do the simple math]
k= 63 ÷ by -7
k=-9
Step-by-step explanation:
the product of −1 and −3
(-1)×(-3)
= 3
