Question

a) 5x + 60 = 120

b) 213 - ( x + 25) = 112

c) 5^x - 25 = 100

Answer 1

a)

\(5x+60=120\)

\(\Rightarrow5x=120-60\)

\(\Rightarrow5x=60\)

\(\Rightarrow x=60\div5\)

\(\Rightarrow x=12\)

Vậy \(x=12\)

b)

\(213-\left(x+25\right)=112\)

\(\Rightarrow x+25=213-112\)

\(\Rightarrow x+25=101\)

\(\Rightarrow x=101-25\)

\(\Rightarrow x=76\)

Vậy \(x=76\)

c)

\(5^x-25=100\)

\(\Rightarrow5^x=100+25\)

\(\Rightarrow5^x=125\)

\(\Rightarrow5^x=5^3\)

\(\Rightarrow x=3\)

Vậy \(x=3\)