Answer:
welp i got -891k - 357 but that seems really big
Explanation:
i distributed the 5 to the -3.4k and the -7 and got -17k-35. then i foiled that out with the 3k+21 and got -51k -357 - 105k -735k. then i combined like terms and got -891k -357
hope this helps rip sorry