1 tính = cách hợp lí
a,36.23+62.23+46
2.tìm x
a,47. x +213=3.7.3.7
b,83+519.x=66.100+22
1 . a) 36.23 + 62.23 + 46 = 36.23 + 62.23 + 46.2
= 23 . ( 36 + 62 + 2 )
= 23 . 100
= 2300
2 : TÌm x :
a . 47 . x + 213 = 3.7.3.7
47. x + 213 = 441
47 . x = 441 - 213
47 . x = 228
x = 228 : 47
x = 4,85
b ) 83 + 519 . x = 66.100 + 22
83 + 519 . x = 6600 + 22
83 + 519 . x = 6622
519 . x = 6622 - 83
519 . x = 6539
x = 6539 : 519
x = 12,599
Bài 1:
a. 36.23+62.23+46
= (36+62).23+46
= 98.23 +46
= 2254 + 46
= 2300
Bài 2:
a. 47. x + 213 = 3.7.3.7
47. x + 213 = 441
47. x = 441 - 213
47 . x = 228
x = 228 : 47
Vậy: x = \(\frac{228}{47}\)
b. 83 + 519.x = 66.100 + 22
83 + 519.x = 6600 + 22
83 + 519.x = 6622
519.x = 6622 - 83
519.x = 6539
x = 6539 : 519
Vậy: x = \(\frac{6539}{519}\)
Bài 2: (1.5 điểm) Tìm x, biết: (83 + 519).x = 66.100 + 22. Kết quả:
(83 + 519).x = 66.100 + 22
602 .x = 6622
x = 6622 : 602
x = 11
\(\left(83+519\right).x=66.100+22\)
\(\Leftrightarrow602.x=6622\)
\(\Leftrightarrow x=6622\div602\)
\(\Rightarrow x=11\)
Vậy x=11
chúc bạn hok tốt.bye
1.tinh = cach hơp li
a.36.23+62.23+46
2.tim x
a,47.x+213=3.7.3.7
b,82+519.x=6.100+22
Câu 2:
a: =>47x+213=21x21=441
=>47x=228
hay x=228/47
b: =>519x=540
=>x=540/519=180/173
[83+519]x=66*100+22
(83 + 519) . x = 66 . 100 + 22
(83 + 519) . x = 6600 + 22
(83 + 519) . x = 6622
602 . x = 6622
x = 6622 : 602
x = 11
Tìm x: a, 213-2x X=47
b, 3x(x+1)-300=906
c,7/3-2/3xX=1/4
d,2/5xX+7/8=2
a) 213 - 2 x X = 47
2 x X = 213 - 47
2 x X = 166
X = 166 : 2
X = 83
b) 3 x ( X + 1 ) - 300 = 906
3 x ( X + 1 ) = 906 + 300
3 x ( X + 1 ) = 1206
X + 1 = 1206 : 3
X + 1 = 402
X = 402 - 1
X = 401
c) \(\frac{7}{3}-\frac{2}{3}\times x=\frac{1}{4}\)
\(\frac{2}{3}\times x=\frac{7}{3}-\frac{1}{4}\)
\(\frac{2}{3}\times x=\frac{25}{12}\)
\(x=\frac{25}{12}:\frac{2}{3}\)
\(x=\frac{25}{8}\)
d) \(\frac{2}{5}\times x+\frac{7}{8}=2\)
\(\frac{2}{5}\times x=2-\frac{7}{8}\)
\(\frac{2}{5}\times x=\frac{9}{8}\)
\(x=\frac{9}{8}:\frac{2}{5}\)
\(x=\frac{45}{16}\)
Học tốt #
a) \(213-2\cdot x=47\)\(\Leftrightarrow2\cdot x=166\Leftrightarrow x=83\)
b)\(3x\left(x+1\right)-300=906\Leftrightarrow3x\left(x+1\right)=606\)
\(\Leftrightarrow x\left(x+1\right)=202\Leftrightarrow x^2+x-202=0\)
\(\Leftrightarrow\left(x+\frac{1}{2}\right)^2-202,25=0\)\(\Leftrightarrow\orbr{\begin{cases}x+\frac{1}{2}=\sqrt{202,25}\\x+\frac{1}{2}=-\sqrt{202,25}\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\sqrt{202,25}-0,5\\x=-\sqrt{202,25}-0,5\end{cases}}\)
a) 213 - 2*x = 47
2*x = 213 - 47
2*x = 126
x = 63
các phần cn lại bn lm tương tự nha!
47 x 83 + 21 x 53 + 47 x 17 - 79 x 53
47 x 83 + 21 x 53 + 47 x 17 - 79 x 53
= 47 x (83 + 17) + 53 x (21 - 79)
= 47 x 100 + 53 x (-58)
= 4700 - 3074
= 1626
47 x 83 + 21 x 53 + 47 x 17 - 79 x 53
\(47.83+21.53+47.17-79.53\)
\(=47.\left(83+17\right)+53.\left(79+21\right)\)
\(=47.100+53.100\)
\(=4700+5300\)
\(=10000\)
Thực hiện phép tính
a) 97 x 24 + 6 x 437 x 2 + 3 x 369 x4
b) 37 x 213 + 86 x 37 + ( 73 x 47 - 68 x 47 ) : 47
c) 49 + 51 x ( 98 - 49 ) + 27 x ( 62 + 37 ) + 73 x ( 43 + 56 )
Tìm x ϵ N biết :
a) 280 – ( x – 140 ) : 35 = 270 ;
b)( 190 – 2x ) : 35 – 32 = 16;
c) 720 : [ 41 – ( 2x – 5 ) ] = 23 .5
d) ( x : 23 + 45 ) . 37 – 22 = 24 . 105 ;
e) ( 3x – 4 ) . ( x – 1 ) 3 = 0 ;
f) 22x-1 : 4 = 83
g) x17 = x ;
h) ( x – 5 ) 4 = ( x – 5 ) 6 ;
i) ( x + 2 ) 5 = 210 ;
k ) 1 + 2 + 3 + … + x = 78
l) ( 3 .x – 24) . 73 = 2 .74 ;
n) 5x : 52 = 125 ;
m) ( x + 1) 2 = ( x + 1) 0 ;
o) ( 2 + x ) + ( 4 + x ) + ( 6 + x ) + ……+ ( 52 + x ) = 780 ;
p) 70⋮ x , 80 ⋮ x và x > 8
q) x ⋮ 12 , x ⋮ 25 , x ⋮ 30 và 0 < x < 500
