Question

Answer 1

a: \(225:15+3\left(2x+1\right)=270\)

=>15+3(2x+1)=270

=>3(2x+1)=270-15=255

=>2x+1=85

=>2x=84

=>x=42

c: \(3\left(2x+1\right)^3=81\)

=>\(\left(2x+1\right)^3=\frac{81}{3}=27=3^3\)

=>2x+1=3

=>2x=2

=>x=1

d: \(\left(x+1\right)^5=243\)

=>\(\left(x+1\right)^5=3^5\)

=>x+1=3

=>x=2

g: \(7^{x}+7^{x+1}+7^{x+2}=3\cdot19\cdot343\)

=>\(7^{x}+7^{x}\cdot7+7^{x}\cdot49=57\cdot343\)

=>\(7^{x}\left(1+7+49\right)=57\cdot343\)

=>\(7^{x}=343\)

=>x=3