Cho phươnh trình \(x^2-2\left(m-1\right)x^2+m^2-3m=0\)

a. Tìm m để pt có 2 nghiệm \(x_1,x_2\)

b. Tìm GTNN của biểu thức B = \(x_1^2+x_2^2+7\)

my brother is not good at playing tennis

My brother does not .............

he couldn't come............. because he was ill

A large number of inhabitants have made ......... on how to protect the environment

A. suggest

B. to suggest

C. suggestion

D. suggested