\(\text{⇒lá+lá+lá+sâu+sâu+sâu+táo+táo+táo=15+9+30}\)

\(\text{3 lá+3 sâu+3 táo=54}\)

\(\text{3(lá+sâu+táo)=54}\)

\(\text{⇒lá+sâu+táo=54:3=18}\)

\(\text{TBC các số đó là:}\)

\(\text{(211+213+215+217+219):5=215}\)

\(\text{35-5.(x+2)=10}\)

\(\text{5.(x+2)=35-10}\)

\(\text{5.(x+2)=25}\)

\(\text{x+2=25:5}\)

\(\text{x+2=5}\)

\(\text{x=5-2}\)

\(\text{x=3}\)

\(\text{112-2(x-1)=2^5}\)

\(\text{2(x-1)=112-32}\)

\(\text{x-1=80:2}\)

\(\text{x-1=40}\)

\(\text{x=40+1}\)

\(\text{x=41}\)

\(8^8+8^7+8^6=8^6.8^2+8^6.8+8^6.1\)

\(=8^6\left(1+8+8^2\right)\)

\(=8^6\left(9+64\right)\)

\(=8^6.73\text{⋮}73\)

x + 30% + x = 1,3

x + 3/10 + x = 1,3

2x + 3/10 = 1,3

2x = 1,3 - 3/10

2x = 1

x = 1/2

x = 0,5.