9.2+(x+25)=100
18+(x+25)=100
x+25=100-18
x+25=82
x=82-25
x=57
155-10.(x+1)=55
10.(x+1)=155-55
10.(x+1)=100
x+1=100/10
x+1=10
x=10-1
x=9
a)9.2+(x+25)=100
18+x+25=100
43+x=100
=>x=100-43=57
b)155-10(x+1)=55
155-10x+10=55
10x+10=155-55
10x+10=100
10x=100-10=90
x=\(\frac{90}{100}\)=\(\frac{9}{10}\)
18+x+25=100
18+x = 100-25
18+x=75
x = 75-18
x=57
10.(x+1)=155-55
10.(x+1)=100
x+1=100:10
x+1=10
x=10-1
x=9 k cho mk na