x+15×3=48 3x-7=20
x+45=48 3x=27
x=3 x=9
12×5+4x=78.4 8x-19=5
60+4x=78.4 8x=24
4x=18.4 x=3
x=4.6
4【x+5】=60 9x-3×7=33
x+5=15 9x=54
x=10 x=6 .