a)
5.(12-x)-20=30
⇒60-5x-20=30
⇒-5x=30+20-60
⇒-5x=-10
⇒x=2
b)(17x - 25 ) : 8 + 65 = 92
(17x - 25 ) : 8 + 65 = 81
17x - 25 = 16 x 8 = 128
17x = 128+25=153
x= 153:17 =9
c)
x=23
Giải thích các bước giải:
3x – 10 = 2x + 13
3x-2x=13+10
x=23
d)4(2x+7)-3(3x-2)=24
4.2x+4.7-3.3x+3.2=24
8x+28-9x+6=24
8x-9x=24-28-6=-10
=>(-1)x=-10
x=-10:(-1)
x=10
a. \(5\cdot\left(12-x\right)-20=30\Leftrightarrow5\left(12-x\right)=50\)
\(\Leftrightarrow12-x=50:5=10\)
\(\Leftrightarrow x=12-10=2\)
b. \(\left(17x-25\right):8+65=9^2\)
\(\Leftrightarrow\left(17x-25\right):8=81-65=16\)
\(\Leftrightarrow17x-25=16:8=2\)
\(\Leftrightarrow17x=2+25=27\Leftrightarrow x=\frac{27}{17}\)
c. \(3x-10=2x+13\)
\(\Leftrightarrow3x-2x=10+13\)
\(\Leftrightarrow x=23\)
d. \(4\cdot\left(2x+7\right)-3\cdot\left(3x-2\right)=24\)
\(\Leftrightarrow8x+28-9x+6=24\)
\(\Leftrightarrow34-x=24\Leftrightarrow x=10\)
a)
5.(12-x)-20=30
⇒60-5x-20=30
⇒-5x=30+20-60
⇒-5x=-10
⇒x=2
b)(17x - 25 ) : 8 + 65 = 92
(17x - 25 ) : 8 + 65 = 81
17x - 25 = 16 x 8 = 128
17x = 128+25=153
x= 153:17 =9
c)
x=23
Giải thích các bước giải:
3x – 10 = 2x + 13
3x-2x=13+10
x=23
d)4(2x+7)-3(3x-2)=24
4.2x+4.7-3.3x+3.2=24
8x+28-9x+6=24
8x-9x=24-28-6=-10
=>(-1)x=-10
x=-10:(-1)
x=10
a)5(12-x)-20=30
<=> 60-5x-20=30
<=> 40-5x=30
<=> 5x=40-30=10
<=> x=10:5=2
Vậy x=2
b)(17x-25):8+65=92
<=>(17/8)x-25/8 +65 =81
<=> (17/8)x+495/8=81
<=>(17/8)x=153/8
<=> x= 9
Vậy x=9
c)3x-10=2x+13
<=> 3x-2x=13+10=23
<=> x=23
d)4(2x+7)-3(3x-2)=24
<=> 8x+28-9x+6=24
<=>-x=24-6-28
<=>-x=-10
<=>x=10
Vậy x=10
a) 5.(12 - x) - 20 = 30
5.(12 - x) = 30 + 20
5.(12 - x) = 50
12 - x = 50 : 5
12 - x = 10
x = 12 - 10
x = 2
vậy x = 2
b) (17x - 25) : 8 + 65 = 9^2
(17x - 25) : 8 + 65 = 81
(17x - 25) : 8 = 81 - 65
(17x - 25) : 8 = 16
17x - 25 = 16.8
17x - 25 = 128
17x = 128 + 25
17x = 153
x = 9
vậy x = 9
c) 3x - 10 = 2x + 13
=> 3x - 2x = 13 + 10
=> x = 23
vậy x = 23
d) 4.(2x + 7) - 3.(3x - 2) = 24
4.2x + 4.7 - 3.3x + 3.2 = 24
8x + 28 - 9x + 6 = 24
-x + 34 = 24
-x = 24 - 34
-x = -10
=> x = 10
vậy x = 10
k cho mk nha
a)5 . ( 12 - x ) - 20 = 30
5. ( 12-x)= 30 + 20
5. ( 12-x)=50
( 12-x ) = 50 : 5 = 10
x= 12 - 10 = 2
b)( 17x - 25 ) : 8 + 65 = 9²
( 17x - 25 ) : 8 + 65 = 81
( 17x - 25 ) : 8 = 81 - 65
( 17x - 25 ) : 8 = 16
( 17x - 25 ) = 16 . 8 = 128
17x = 128 + 25 = 153
x= 153 : 17 = 9
c)3x - 10 = 2x + 13
3x - 2x = 13 + 10
x = 23
d) 4 . ( 2x + 7 ) - 3 . ( 3x - 2 ) = 24
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