Question

Answer 1

a: Đặt A=\(x\left(x-y\right)+y\left(x-y\right)\)

=(x-y)(x+y)

Khi x=13;y=3 thì \(A=\left(13-3\right)\left(13+3\right)=10\cdot16=160\)

b: Đặt B=x(x-1)-y(1-x)

\(=x\left(x-1\right)+y\left(x-1\right)\)

=(x-1)(x+y)

Khi x=101 và y=2024 thì \(B=\left(101-1\right)\left(101+2024\right)\)

\(=100\cdot2125=212500\)

Answer 2

a, \(x\left(x-y\right)+y\left(x-y\right)=\left(x+y\right)\left(x-y\right)\)

Thay x = 13 ; y = 3 ta được 

\(16.10=160\)

b, \(x\left(x-1\right)-y\left(1-x\right)=\left(x+y\right)\left(x-1\right)\)

Thay x = 101 ; y = 2024 

\(2125.100=212500\)