310+x=720-120 . у-18 =980-120. 29-8+b=540

Question

310+x=720-120 . у-18 =980-120. 29-8+b=540

Answer 1

310+х=720-120
х=-310+720-120
х=290

у-18=980-120
у=18+980-120
у=878

29-8+б=540
б=-29+8+540
б=519