第1个回答 2024-01-15
解：解方程, 此方程的解为x = 21/10，【即x = 2.1】
3(x + 1.4) = 10.5
3x + 3 × 1.4 = （10×10+5）/10
3x + 3 × （1×10+4）/10 = 105/10
3x + 3 × 14/10 = 21/2
3x + 3 × 7/5 = 21/2
3x + 21/5 = 21/2
3x = 21/2 - 21/5
3x = 105/10 - 42/10
3x = 63/10
x = 63/10 ÷ 3
x = 63/10 × 1/3
x = 21/10
∴x = 2.1
答：此方程的解为x = 21/10，【即x = 2.1】