\(a,x^3-1=-28\\ \Leftrightarrow x^3=-27\\ \Leftrightarrow x^3=\left(-3\right)^3\\ \Leftrightarrow x=-3\\ b,\left(y-1\right)^2-32=-23\\ \Leftrightarrow\left(y-1\right)^2=9\\ \Leftrightarrow\left[{}\begin{matrix}y-1=3\\y-1=-3\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}y=4\\y=-2\end{matrix}\right.\\ c,15-16:\left|x\right|=-1\\ \Leftrightarrow16:\left|x\right|=16\\ \Leftrightarrow\left|x\right|=1\\ \Leftrightarrow x=\pm1\)

A

Mk ko hiểu lắm

ai giảng hộ được ko ?

.

Hoctot

a: Ta có: \(100-7\left(x-5\right)=58\)

\(\Leftrightarrow7\left(x-5\right)=42\)

\(\Leftrightarrow x-5=6\)

hay x=11

b: Ta có: \(12\left(x-1\right):3=4^3+2^3\)

\(\Leftrightarrow12\left(x-1\right)=216\)

\(\Leftrightarrow x-1=18\)

hay x=19

hình như lớp 8 mà mình bấm bị lộn ai bik chỉ mình vs

a)  3x( 2x + 3) -(2x+5)(3x-2)=8

<=> 6x^2+9x-6x^2+4x-15x+10=8

<=> -2x+10=8

<=> -2x= 8-10 = -2

<=> x=1

b)  (3x-4)(2x+1)-(6x+5)(x-3)=3

<=> 6x^2+3x-8x-4-6x^2+18x-5x+15=3

<=> -8x+11=3

<=> -8x= -8

<=> x=1

c, 2(3x-1)(2x+5)-6(2x-1)(x+2)=-6

<=> 2(6x^2+15x-2x-5)-6(2x^2+4x-x-2)=6

<=> 2(6x^2+13x-5)-6(2x^2+3x-2)=6

<=> 12x^2+ 26x-10-12x^2-18x+12=6

<=> 8x+2=6

<=> 8x=4

<=> x= 1/2

d, 3xy(x+y)-(x+y)(x^2 +y^2+2xy)+y^3=27

<=> 3x²y+3xy²-(x+y)(x+y)²+y³=27

<=> 3x²y+3xy²-(x+y)³+y³=27

<=> 3x²y +3xy² -x³-3x²y-3xy²-y³+y³=27

<=> -x³=27

<=> x= \(-\sqrt[3]{27}\)= -3

Bài 2: 

a: Ta có: \(2^{x+1}\cdot3^y=12^x\)

\(\Leftrightarrow2^{x+1}\cdot3^y=2^{2x}\cdot3^x\)

\(\Leftrightarrow\left\{{}\begin{matrix}x+1=2x\\x=y\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\y=1\end{matrix}\right.\)

1.A.0.96

Câu a tự làm nhé

b, \(\frac{2x+3}{24}=\frac{3x-1}{32}\)

\(\Leftrightarrow32(2x+3)=24(3x-1)\)

\(\Leftrightarrow64x+96=72x-24\)

\(\Leftrightarrow64x+96-72x=-24\)

\(\Leftrightarrow96-8x=-24\Leftrightarrow x=15\)

2. a. \(\frac{x}{3}=\frac{y}{4}=\frac{z}{6}\) và x + y + z = 52

Ta có : \(\frac{x}{3}=\frac{y}{4}=\frac{z}{6}=\frac{x+y+z}{3+4+6}=\frac{52}{13}=4\)\((\)áp dụng tính chất dãy tỉ số bằng nhau \()\)

Vậy : \(\hept{\begin{cases}\frac{x}{3}=4\\\frac{y}{4}=4\\\frac{z}{6}=4\end{cases}}\Leftrightarrow\hept{\begin{cases}x=12\\y=16\\z=24\end{cases}}\)