Câu 2.1, 2.1, 2.3 trang 7, 8 Sách Bài Tập SBT Toán lớp 7 tập 1

By Cuồng Review On Jul 19, 2022

Câu 2.1 trang 7 Sách Bài Tập SBT Toán lớp 7 tập 1
Số ({{ – 7} over {12}}) là tổng của hai số hữu tỉ âm:
(A) ({{ – 1} over {12}} + {{ – 3} over 4});
(B) ({{ – 1} over 4} + {{ – 1} over 3});
(C) ({{ – 1} over {12}} + {{ – 4} over 6});
(D) ({{ – 1} over 6} + {{ – 3} over 2}).
Hãy chọn đáp án đúng.
Giải
Chọn (B) ({{ – 1} over 4} + {{ – 1} over 3}).
Câu 2.2 trang 7 Sách Bài Tập SBT Toán lớp 7 tập 1
Tổng ({a over b} + {{ – a} over {b + 1}}) bằng:
(A) ({a over {b(b + 1)}});
(B) 0;
(C) ({1 over {b(b + 1)}});
(D) ({{2ab} over {b(b + 1)}} + 1).
Hãy chọn đáp án đúng.
Giải
Chọn (A) ({a over {b(b + 1)}}).
Câu 2.3 trang 8 Sách Bài Tập SBT Toán lớp 7 tập 1
Kết quả của phép tính ({2 over 3} + {1 over 3}.{{ – 6} over {10}}) là:
(A) ({{ – 6} over {10}});
(B) ({7 over {15}});
(C) ({{ – 7} over {15}});
(D) ({6 over {10}}).
Chọn đáp án đúng.
Giải
Chọn (B) ({7 over {15}}).