240180÷{40÷

180÷3加未知数除以4=120? -
180 × 1/3 + x ÷ 4 = 120 180/3 + x ÷ 4 = 120 60 + x ÷ 4 = 120 x ÷ 4 = 120 - 60 x ÷ 4 = 60 x = 60 × 4 ∴x = 240 答：180÷3加240除以4等于120