Cho hệ vector U={(1,2,8);(0,-1,-7);(2,3,9);(1,0,- 6)} a) tìm số chiều và 1 cơ sở W của không gian con sinh bởi hệ vector U
b) tìm tham số k để u=(2,3,k^2+1) là 1 tổ hợp tuyến tính của W và tính [u]w

One-third of the people from country a claim that they are from country b, and the rest admit they are from country a. one-fourth of the people from country claim that they are from country a, and the rest admit they are from country b. in a combined census of the two countries, one-half of the total claimed to be from a. what is the ratio of the populations of country a to that of country b.

Write an expression that has three terms and simplifies to 4x - 7. identify the coefficient(s) and constant(s) in your expression

What are the solutions of the system? solve by graphing. y = -x^2 -6x - 7 y = 2