Question

Answer 1

1:

1:

a: \(=10^3-3\cdot\left\{400-673+2^3\left(7^2+1\right)\right\}\)

\(=1000-3\left\{-273+8\cdot50\right\}\)
=1000-3*127

=619

b: \(Q=\dfrac{2^6\cdot3^4+2^6\cdot3^4\cdot5}{-2^6\cdot3^6+2^5\cdot3^5}=\dfrac{2^6\cdot3^4\cdot6}{-2^5\cdot3^5\left(2\cdot3-1\right)}\)

\(=\dfrac{-2}{3}\cdot\dfrac{6}{5}=\dfrac{-4}{5}\)

II:

1: =>(2x-15)^3[(2x-15)^2-1]=0

=>(2x-15)(2x-14)(2x-16)=0

=>x=15/2;x=7;x=8

2: 2xy-x-y=2

=>x(2y-1)-y+1/2=5/2

=>(y-1/2)(2x-1)=5/2

=>(2x-1)(2y-1)=5

=>(2x-1;2y-1) thuộc {(1;5); (5;1); (-1;-5); (-5;-1)}

=>(x,y) thuộc {(1;3); (3;1); (0;-2); (-2;0)}