33-а=90-70,17+х=33+27,70-в=88-45
33-а=90-70 33-а=20 -а=20-33 -а=-13 а=13 17+х=33+27 17+х=60 х=60-17 х=43 70-в=88-45 70-в=43 -в=43-70 -в=-27 в=27