Question

tinh :

10 . 58 .5 + 32 . 2 .25 + 50 .10

20 - 2 . [ x - 1 ] = 4

[ x + 1 mũ 2 ]= 9

Answer 1

10 . 58 . 5 + 32 . 2 . 25 + 50 . 10
= 50 . 58 + 50 . 32 + 50 . 10
= 50 . ( 58 + 32 + 10 )
= 50 . 100
= 5000
20 - 2 . ( x - 1 ) = 4
\(\Rightarrow\)2 . ( x - 1 ) = 16
\(\Rightarrow\)x - 1 = 16 : 2
\(\Rightarrow\)x - 1 = 8
\(\Rightarrow\)x = 9
( x + 1 )² = 9 = 3² = ( -3 )²

\(\Rightarrow\orbr{\begin{cases}x+1=3\\x+1=-3\end{cases}\Rightarrow\orbr{\begin{cases}x=3-1\\x=3+1\end{cases}\Rightarrow}\orbr{\begin{cases}x=2\\x=4\end{cases}}}\)

Answer 2

a,=50.28+32.50+50.10=50.(28+32+10)=50.70=3500

b.2(x-1)=20-4

x-1=16/2

x=8+1=9

c,