Like earlier take the bigger shape and divide the smaller one.
8.4 divide by 4 and you get 2.1.
The answer to your Q the better one it is the 4- pound bag because it coast less money
We need to FOIL that out and then get it into standard form to see what our A, B, and C are. FOILing gives us

. If we move the 7 over by subtraction and set it equal to 0, we have

. In order to avoid a negative leading coefficient, we can change all the signs to get

so A = 1, B = 0, C = -18, first choice above.
2r²+15r-50
hope this helps