Cine mă poate ajuta?

Răspuns:
a)867×13-509×19+400×4=1000÷25+1325×12-637×20
=11271-9671+1600=40+15900-12740
3200=3200 (A)
b)3001-15×15+1025÷25=1905+17×301-307×18
=3001-225+41=1905+5117-5526
2817=1496 (F)