Kiểm tra 45 phút môn: Đại số lớp 8

Họ và tên:.................................. Điểm Lớp:........................................... Kiểm tra 45 phút Môn: đại số lớp 8 Lời phê của thầy, cô giáo Thứ ngày tháng năm 2006 Đề bài : I. Trắc nghiệm: (3đ) Đánh dấu "x" vào dòng, cột thích hợp: Câu Đúng Sai 1/ x2 - y2 = y2 - x2 2/ x2 - y2 = - (y2 - x2) 3/ [3(x - y)3 + 2(x - y)2 - x + y] : (x - y) = 3(x - y)2 + 2x - 2y + 1 4/ (- x - y)3 = (x + y)3 5/ (- x - y)6 = (x + y)6 II. Tự luận: 7 điểm 1/ Tính nhanh: 872 + 132 + 26.87 2/ Rút gọn biểu thức: (2x + 1)2 + 2(4x2 - 1) + (2x - 1)2 3/ Phân tích thành nhân tử: a. x2 - y2 - 5x + 5y b. 2x2 - 5x - 7 4/ Tìm x biết: 5x(x - 1) = x - 1 5/ Tìm a để đa thức x3 - 3x2 + 5x + a chia hết cho đa thức x - 2 6/ Chứng minh rằng: - x2 + 2x - 2 < 0 với mọi giá trị của x. 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