Question

13 x( 7-x ) = 26

5 x ( x-9)=15
 

Answer 1

a) \(13.\left(7-x\right)=26\)

\(7-x=26:13\)
\(7-x=2\)
\(x=7-2\)
\(x=5\)

b() \(5.\left(x-9\right)=15\)
\(x-9=15:5\)
\(x-9=3\)
\(x=3+9\)
\(x=12\)

Answer 2

\(13X\left(7-x\right)=16\)

\(=>7-x=\frac{16}{13}\)

\(=>x=7-\frac{16}{13}\)

\(=>x=\frac{75}{13}\)

\(5X\left(x-9\right)=15\)

\(=>x-9=3\)

\(=>x=9+3\)

\(=>x=12\)

Answer 3

Ta có: \(13.\left(7-x\right)=26\)

\(\Rightarrow7-x=26:13=2\)

\(\Rightarrow x=7-2=5\)

Vậy x = 5

Ta có: \(5.\left(x-9\right)=15\)

\(\Rightarrow x-9=15:5=3\)

\(\Rightarrow x=3+9=12\)

Vậy x = 12