7+5+5+7+(-4)+X+(-223)-X=64 thì X=?
Các thầy cô vs các ac ơi giúp e vs ạ
Tính tổng sau bằng cách hợp lý:
10. -[-171 + 171 + 223] - [172 - 105 + 172] + 223
Tìm x:
1. -x-3 = 7
2. x + 5 = -10
3. 2.x -7 = 713
4. -129-(35 - x) = 55
5. 103 - x = 16 - ( 13 - 8)
E cần gấp, e cảm ơn trước ạ!
1) -x - 3 = 7
-x = 7 + 3
-x = 10
x = -10
2) x + 5 = -10
x = -10 - 5
x = -15
3) 2x - 7 = 713
2x = 713 + 7
2x = 720
x = 720 : 2
x = 360
4) -129 - (35 - x) = 55
35 - x = -129 - 55
35 - x = -184
x = 35 - (-184)
x = 219
5) 103 - x = 16 - (13 - 8)
103 - x = 16 - 5
103 - x = 11
x = 103 - 11
x = 192
Tính
a. 7,2 : 2 x 58,6 + 2,93 x 2 x 64
b. 4/2/5 + 2/3/7 - 2/2/5 + 5/4/7 (hỗn số)
c. 2 x 41 x 36 +8 x 9 x 58 + 12 x 6
d. 3/5 x 1/2 : 2/5
e . 1/1/3 x 4/7 + 1/1/3 x 3/7
AI BIẾT THÌ GIÚP MIK NHÉ !
a.7,2 :2 x 58,6 + 2,93 x 2 x 64
= 3,6 x 58,6 + 5,86 x 64
=210,96 + 357,04
=586
b.\(4\frac{2}{5}+2\frac{3}{7}-2\frac{2}{5}+5\frac{4}{7}\)
=\(\left(4\frac{2}{5}-2\frac{2}{5}\right)+\left(2\frac{3}{7}+5\frac{4}{7}\right)\)
= 2 + 8
= 10
c. 2 x 41 x 36 + 8 x 9 x 58 + 12 x 6
=72 x 41 + 72 x 58 + 72 x 1
=72 x ( 41 + 58 +1 )
=72 x 100
=7200
d, \(\frac{3}{5}\)x \(\frac{1}{2}\):\(\frac{2}{5}\)
=\(\frac{3}{5}\)x \(\frac{1}{2}\)x\(\frac{5}{2}\)
=\(\frac{3}{4}\)
bài 1 : Tìm x
a) 5 + ( x + 27 ) = 64
b) 64 - ( x - 2 ) = 25
c) 7 - ( x + 5 ) + 14 = 343
d) 5 . x - 25 = 10
e) 4 . ( x - 5 ) - 8 = 48
f) 49 - ( 15 + x ) = 12
g) 49 - 7. ( 13 - x ) = 14
h) 155 - 10. ( x + 1 ) = 55
5 + ( x + 27 ) = 64
( x + 27 ) = 64 - 5 ( x + 27 ) = 59 x = 59 - 27 x = 32a) \(\Rightarrow x+27=59\Rightarrow x=32\)
b) \(\Rightarrow x-2=39\Rightarrow x=41\)
c) \(\Rightarrow x+5=-322\Rightarrow x=-327\)
d) \(\Rightarrow5x=35\Rightarrow x=7\)
e) \(\Rightarrow4\left(x-5\right)=56\Rightarrow x-5=14\Rightarrow x=19\)
f) \(\Rightarrow15+x=37\Rightarrow x=22\)
g) \(\Rightarrow7\left(13-x\right)=35\Rightarrow13-x=5\Rightarrow x=8\)
h) \(\Rightarrow10\left(x+1\right)=100\Rightarrow x+1=10\Rightarrow x=9\)
Tìm x thuộc Z:
a)x/5-2/3+3/4=17/60
b)1/8-7/5-2/x=-223/120
a)
x/5-2/3+3/4=17/60
<=> x/5=17/60-3/4+2/3
<=> x/5=1/5
<=> x=1
b)
18−75−2x=−22312018−75−2x=−223120
<=> −5140−2x=−223120−5140−2x=−223120
<=>2x=−5140+2231202x=−5140+223120
<=>2x=7122x=712 <=> 7x=2.127x=2.12
<=> x=247x=247
vậyx=247
Tìm x,biết:
A) 8 + ( x - 9)= 125 - 64
B) 5×(x+7) -10 = 8×5
C) 7 × 7 - 7( 13 - 2× x) = 14
D) 320 : (x - 1) = ( 125 - 5 ×5 ) : 4 + 15
E) 240 : ( x -5 ) = 4 × 5 ×5 - 60 : 3
F) 49 × x - 14 × x = 49 × 10 - 70
a. 8 + (x - 9) = 125 - 64
8 + (x - 9) = 61
x - 9 = 53
x = 62
b. 5 x (X + 7) - 10 = 8 x 5
5 x (X + 7) - 10 = 40
5 x (X + 7) = 50
X + 7 = 10
X = 3
Tính theo mẫu :
Mẫu : 13/21 + 5/7 = 13/21 + 5 x 3 / 7 x 3 = 13/21 + 15/21 = 28/21
26/81 + 4/27
5/64 + 7/8
\(\dfrac{26}{81}+\dfrac{4}{27}=\dfrac{26+12}{81}=\dfrac{38}{81}\)
\(\dfrac{5}{64}+\dfrac{7}{8}=\dfrac{5+56}{64}=\dfrac{61}{64}\)
\(\dfrac{26}{81}+\dfrac{4}{27}=\dfrac{26}{81}+\dfrac{4\times3}{27\times3}=\dfrac{26}{81}+\dfrac{12}{81}=\dfrac{38}{81}\)
\(\dfrac{5}{64}+\dfrac{7}{8}=\dfrac{5}{64}+\dfrac{7\times8}{8\times8}=\dfrac{5}{64}+\dfrac{56}{64}=\dfrac{61}{64}\)
Tính bằng cách thuận tiện nhất:
a) 428 x 36 + 64 x 428
b) 512 x 47 - 37 x 512
c) 72 x 4 x 25
d) 4/9 x 3/7 + 5/9 x 3/7
a: =428(36+64)=42800
b: =512(47-37)=5120
c: =72x100=7200
\(428×(36+64)\)
\(=428×100\)
\(=42800\)
\(512×(47-37)\)
\(=512×10\)
\(=5120\)
\(72×(4×25)\)
\(=72×100\)
\(=7200\)
\(\left(\dfrac{4+5}{9}\right)\text{×}\dfrac{3}{7}\)
\(=1\text{×}\dfrac{3}{7}\)
\(=\dfrac{3}{7}\)
a, 428 x 36 + 64 x 428
= 428 x (36 + 64)
= 428 x 100
= 42800
b, 512 x 47 - 37 x 512
= 512 x (47 - 37)
= 512 x 10
= 5120
câu này mik bị lú nên hok lm
d) 4/9 x 3/7 + 5/9 x 3/7
= 3/7 x (4/9 + 5/9)
= 3/7 x 1
= 3/7
Chứng minh rằng:
1) x - 5 > x - 10
2) x - 4 > x - 8
3) x + 2 > x - 6
4) x - 3 < x + 7
5) x + 5 < x + 8
6) x + 10 >x + 7
1: -5>-10
=>x-5>x-10
2: -4>-8
=>x-4>x-8
3: 2>-6
=>x+2>x-6
4: -3<7
=>x-3<x+7
5: 5<8
=>x+5<x+8
6: 10>7
=>x+10>x+7