Question

5×＋7.4＝31.80.7×＋3.4×＝37.72（×－12）÷4＝4.55×（×＋2.4）＝25.53.2×＋1.8

Answer 1

5×＋7.4＝31.8

5x=24.4

x=4.88

0.7×＋3.4×＝37.72

4.1x=37.72

x=9.2

（×－12）÷4＝4.5

x-12=18

x=30

5×（×＋2.4）＝25.5

x+2.4=5.1

x=2.7

3.2×＋1.8×＝3.5

5x=3.5

x=0.7