Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
`@` `\text {Ans}`
`\downarrow`
`a)`
`5(x + 35) = 515`
`=> x + 35 = 515 \div 5`
`=> x+ 35 = 103`
`=> x = 103 - 35`
`=> x = 68`
Vậy, `x = 68`
`b)`
`12x - 33 = 3^2 * 3^3`
`=> 12x - 33 = 3^5`
`=> 12x = 3^5 + 33`
`=> 12x = 276`
`=> x = 276 \div 12`
`=> x = 23`
Vậy, `x = 23`
`c)`
`6x - 5 = 19`
`=> 6x = 19 + 5`
`=> 6x = 24`
`=> x = 24 \div 6`
`=> x = 4`
Vậy, `x = 4`
`d)`
`4(x - 12) + 9 = 17`
`=> 4(x - 12) = 17 - 9`
`=> 4(x - 12) = 8`
`=> x - 12 = 8 \div 4`
`=> x - 12 = 2`
`=> x = 14`
Vậy, `x = 14`
`e)`
123 - 5(x + 4) = 38`
`=> 5(x + 4)= 123 - 38`
`=> 5(x + 4) =85`
`=> x + 4 = 85 \div 5`
`=> x + 4 = 17`
`=> x = 13`
Vậy, `x = 13`
`f)`
`(3x - 2^4) * 7^3 = 2 * 7^4`
`=> 3x - 2^4 = 2 * 7^4 \div 7^3`
`=> 3x - 2^4 = 2* 7`
`=> 3x - 2^4 = 14`
`=> 3x = 14 + 2^4`
`=> 3x = 30`
`=> x = 30 \div 3`
`=> x = 10`
Vậy, `x = 10.`
123 - 5 . ( x + 4 ) = 38
5 . ( x + 4 ) = 123 - 38
5 . ( x + 4 ) = 85
x + 4 = 85 : 5
x + 4 = 17
x = 17 - 4
x = 13
( 3x - 24 ) . 73 = 2 . 74
( 3x - 16 ) . 343 = 2 . 2401
( 3x - 16 ) . 343 = 4802
3x - 16 = 4802 : 343
3x - 16 = 14
3x = 14 + 16
3x = 30
x = 30 : 3
x = 10
123 - 5( x + 4 ) = 38
=> 5( x + 4 ) = 123 - 38
=> x + 4 = 85 ÷ 5
=> x = 17 - 4
=> x = 13
(3x - 24 ) · 73 = 2·74
=> ( 3x - 16 ) = 2 . 74 ÷ 73
=> 3x - 16 = 14
=> 3x = 16 + 14
=> x = 30 ÷ 3
=> x = 10
Q=1.2.(3-1)+2.3.(4-1)+3.4.(5-1)+...+19.20.(21-1)=
=(1.2.3+2.3.4+3.4.5+...+19.20.21)-(1.2+2.3+3.4+...+19.20)
Đặt
A=1.2.3+2.3.4+3.4.5+...+19.20.21
4A=1.2.3.4+2.3.4.4+3.4.5.4+...+19.20.21.4=
=1.2.3.4+2.3.4(5-1)+3.4.5.(6-2)+...+19.20.21.(22-18)=
=1.2.3.4-1.2.3.4+2.3.4.5-2.3.4.5+3.4.5.6-...-18.19.20.21+19.20.21.22=
=19.20.21.22
\(A=\dfrac{19.20.21.22}{4}=5.19.21.22\)
Đặt
B=1.2+2.3+3.4+...+19.20
3B=1.2.3+2.3.3+3.4.3+...+19.20.3=
=1.2.3+2.3.(4-1)+3.4.(5-2)+...+19.20.(21-18)=
=1.2.3-1.2.3+2.3.4-2.3.4+3.4.5-...-18.19.20+19.20.21=
=19.20.21
\(B=\dfrac{19.20.21}{3}=7.19.20\)
Q=A-B
\(\left[8x-120:4\right]\times3^3=3^6.\)
\(8x-120:4=3^3\)
\(8x-30=27\)
\(8x=27+30\)
\(8x=57\)
\(x=19\)
123 - 5.(x + 4) = 38
123 - 5x - 20 = 38
-5x = 38 - 123 + 20
-5x = -65
x = -65 : -5
x = 13
Vậy x = 13
123-3.(3x-5) = 3.42
<=>123 -9x+15 = 3.16
<=>138-9x = 48
<=>9x = 90
<=>x = 10
Vậy x = 10
x=10 nha