a 49 x 77 - 302 + 23 x 49
4) -23 +x = - (- 25) 5) -5 ≤ x < 6 | 6) 140 : (x – 8) = 7 7) -4(x + 41) = 400 8) 2x – 49 = 5 . 32 |
6: \(\Leftrightarrow x-8=20\)
hay x=28
Bài 1:tính hợp lý:
a) 49. 77- 302+ 23. 49
b) 44. 77- 202+ 23. 44
a) =49x(77+23) -30^2
= 49 x100 -900
= 4900-900 = 4000
b) =44x( 77+23) -20^2
= 44x100 -400
= 4400-400 = 4000
Hok hành chăm chỉ nha
a) 49. 77- 302+ 23. 49
= 49 . 77 + 23 . 49 - 302
= 49 . ( 77 + 23 ) - 900
= 49 . 100 - 900
= 4900 - 900
= 4000
b) 44. 77- 202+ 23. 44
= 44 . 77 + 23 . 44 - 202
= 44 . ( 77 + 23 ) - 400
= 44 . 100 - 400
= 4400 - 400
= 4000
~ HOK TỐT ~
a, 49 . 77 - 302 + 23.49
=49( 77 + 23) - 900
=4900 - 900
=4000
b, 44.77 - 202 + 23.44
=44.( 77 + 23) - 400
=4400 - 400
=4000
(-2)5+[(-7)3:49+23]:(-2)
128(278-302)+278(302-128)
tính hợp lý (nếu được)
23 . 49 +77 .177 + 23 .61-77 . 67
23.49+77.177+23.61-77.67
=23.(49+61)+77.(177-67)
=23.110+77.110
=110.(23+77)
=110.100=11000
k nha
23 * 49 + 77*177 + 23*61 - 77* 67 = 23(49+ 61) + 77 (177 - 67) = 23* 110 + 77* 110 = (23+ 77) * 110 = 100 * 110 = 11 000
Tìm x biết:
a , 4 9 + x = - 5 3 b , 2 3 + 3 5 : x = 1 7 10 c , 40 % x - 3 5 x = 2 35 d , 2 x + 1 2 = 49
49.(-23+2.x)=(-49).(-23+14)
49. (-23 + 2.x) = (-49).(-23 + 14)
49. (-23 + 2.x) = (-49). (-9)
49. (-23 + 2.x) = 441
-23 + 2.x = 441 : 49
-23 + 2.x = 9
2.x = 9 - (-23)
2.x = 32
x = 32 : 2
x = 16
11/4 x 49 : 77/2=...
\(\dfrac{11}{4}\) \(\times\) 49 : \(\dfrac{77}{2}\)
= \(\dfrac{11}{4}\) x 49 x \(\dfrac{2}{77}\)
= \(\dfrac{11\times7\times7\times2}{4\times11\times7}\)
= \(\dfrac{7}{2}\)
\(\dfrac{11}{4}.9:\dfrac{77}{2}\)
\(=\dfrac{11}{4}.9.\dfrac{22}{7}\)
\(=\dfrac{11.7.7.2}{4.11.7}\)
\(=\dfrac{7}{2}\)
5 x 7 x 77 - 7 x 60 + 49 x 25 - 15 x42
23 x 50 + 49 x 23 + 23
23 x 50 + 49 x 23 + 23
= 23 x 50 + 49 x 23 + 23 x 1
= 23 x ( 50 + 49 + 1 )
= 23 x 100
= 2300
23 x 50 + 49 x 23 + 23
= 1150 + 1129 + 23
= 2302
23 x 50 + 49 x 23 + 23
= 23 x ( 50 + 49 + 1 )
= 23 x 100
= 2300