Х×4=350-70 4-80=7200:10
X×4=280 x=280÷4 x=70 70×4=280
Х•4=350-70. х•4=280 х=280:4 х=70 4х-80=7200:10 4х-80=720 4х=720+80 4=800 х=800:4 х=200