《2025年同步指导素养评价与归类复习测试卷五年级数学上册人教版》

2. 解方程。(每题 3 分,共 24 分)
8x + 2 = 38 & x ÷ 0.85 = 2.5 × 4 \\
3x + 5x = 6.4 & 10.5x - 3.7x = 34 \\
x + 3.8 × 3 = 20 & 2x - 7.5 = 12.5 \\
(x - 8) ÷ 5 = 9 & 8(x + 1.2) = 40

答案： 1. $8x + 2 = 38$
解：$8x = 38 - 2$
$8x = 36$
$x = 36 ÷ 8$
$x = 4.5$
2. $x ÷ 0.85 = 2.5 × 4$
解：$x ÷ 0.85 = 10$
$x = 10 × 0.85$
$x = 8.5$
3. $3x + 5x = 6.4$
解：$8x = 6.4$
$x = 6.4 ÷ 8$
$x = 0.8$
4. $10.5x - 3.7x = 34$
解：$6.8x = 34$
$x = 34 ÷ 6.8$
$x = 5$
5. $x + 3.8 × 3 = 20$
解：$x + 11.4 = 20$
$x = 20 - 11.4$
$x = 8.6$
6. $2x - 7.5 = 12.5$
解：$2x = 12.5 + 7.5$
$2x = 20$
$x = 20 ÷ 2$
$x = 10$
7. $(x - 8) ÷ 5 = 9$
解：$x - 8 = 9 × 5$
$x - 8 = 45$
$x = 45 + 8$
$x = 53$
8. $8(x + 1.2) = 40$
解：$x + 1.2 = 40 ÷ 8$
$x + 1.2 = 5$
$x = 5 - 1.2$
$x = 3.8$