Đáp án:
↓↓
Giải thích các bước giải:
`a)`
`5 × x + x ÷ 0.5 + 2 × x + x = 75/100`
`= 5 × x + x × 2 + 2 × x + x × 1 = 75/100`
`= x × (5 + 2 + 2 + 1) = 75/100`
`= x × 10 = 75/100`
`x = 75/100 ÷ 10`
`x = 75/1000`
`b)`
`3/4 + x + x ÷ 0.2 + 5 × x - x × 0.75 = 1 × 1/4`
`3/4 + x + x ÷ 0.2 + 5 × x - x × 0.75 = 1/4`
`= 0.75 + x + x × 5 + 5 × x - x × 0.75 = 0.25`
`= x × (5 + 5 - 0.75) + 0,75 = 0.25`
`= x × 9.25 + 0.75 = 0.25`
`= x × 9.25 = 0.75 - 0.25`
`= x × 9.25 = 0.5`
`x = 9.25 ÷ 0.5`
`x = 18.5`
`c)`
`3/2 × x + x ÷ 1/4 + x × 150% + x × 3 = 125%`
`= 1.5 × x + x ÷ 0.25 + x × 1.5 + x × 3 = 1.25`
`= x × (1.5 + 0.25 + 1.5 + 3) = 1.25`
`= x × 6.25 = 1.25`
`x = 1.25 ÷ 6.25`
`x = 0.2.`
