Bài 1: Tính nhanh
A) 1+2-3+4+5+6-7-8+……+299-300+301+302
B) 123 . 4564 – 456 . 123123
C). ( 98. 7676-9898. 76) : ( 2004. 2002 …….2020)
Bài 2 : Tìm x
a) ( x+74) – 318 = 200
b) 3636:(12x – 91) =36
c ) ( x:23+45) . 67= 8911
Bài 1: Tính nhanh A) 1+2-3+4+5+6-7-8+……+299-300+301+302 B) 123 . 4564 – 456 . 123123 C). ( 98. 7676-9898. 76) : ( 2004. 2002 …….2020) Bài
By Eden
Đáp án:
1
A) 1+2-3+4+5+6-7-8+……+299-300+301+302
= ((302-1)+1) . ( 302 + 1 ) : 2
= 45753
123 . 4564 – 456 . 123123
= 123 . 4564 – 456456 . 123
= 123 ( 4564 – 456456 )
= 123 . ( – 451892 )
= – 55582716
C). ( 98. 7676-9898. 76) : ( 2004. 2002 …….2020)
= 0 : ( 2004. 2002 …….2020)
= 0
2
a) ( x+74) – 318 = 200
x + 74 = 518
x = 444
b) 3636:(12x – 91) =36
12x – 91 = 101
12x = 10
x = 5 / 6
c ) ( x:23+45) . 67= 8911
x : 23 + 45 = 133
x : 23 = 88
x = 2024
CHO MIK CÂU TRẢ LỜI HAY NHẤT NHÉ
Giải thích các bước giải:
1 A,1+2-3+4+5+6-7-8+……+299-300+301+302= ((302-1)+1) . ( 302 + 1 ) : 2 = 45753123 . 4564 – 456 . 123123= 123 . 4564 – 456456 . 123= 123 ( 4564 – 456456 )= 123 . ( – 451892 ) = – 55582716C). ( 98. 7676-9898. 76) : ( 2004. 2002 …….2020)= 0 : ( 2004. 2002 …….2020)= 02 a) ( x+74) – 318 = 200 x + 74 = 518 x = 444b) 3636:(12x – 91) =36 12x – 91 = 101 12x = 10 x = 5 / 6c ) ( x:23+45) . 67= 8911 x : 23 + 45 = 133 x : 23 = 88 x = 2024