\(\left(x-1\right)^2+\left(y+2\right)^2=0\)

Vì \(\left(x-1\right)^2\ge0\forall x\)

       \(\left(y+2\right)^2\ge0\forall y\)

Nên \(\left(x-1\right)^2+\left(y+2\right)^2\ge0\) \(\Leftrightarrow\orbr{\begin{cases}\left(x-1\right)^2=0\\\left(y+2\right)^2=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x-1=0\\y+2=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=1\\y=-2\end{cases}}\)

Vậy x = 1 và y = -2

\(1) 420+65.4=(x+175):5+30\)

\(\implies 420+260=(x+175):5+30\)

\(\implies 680=(x+175):5+30\)

\(\implies 650=(x+175):5\)

\(\implies 650.5-175=x\)

\(\implies 3075=x\)

\(2)x-4867=(175.2050.70):25+23\)

\(\implies x-4867=1004500+23\)

\(\implies x-4867=1004523\)

\(\implies x=1009390\)

\(3) 134-[(96-7x):4-2]=126\)

\(\implies (96-7x):4-2=8\)

\(\implies(96-7x):4=10\)

\(\implies 96-7x=40\)

\(\implies 7x=56\)

\(\implies x=8\)

\(4) 4-\{100-[(100-5x):8-5]:10\}:25=0\)

\(\implies 4-\{100-[(100-5x):8-5]:10\}=0\)

\(\implies 100-[(100-5x):8-5]:10=4\)

\(\implies 100-[(100-5x):8-5]=40\)

\(\implies (100-5x):8-5=60\)

\(\implies (100-5x):8=65\)

\(\implies 100-5x=520\)

\(\implies 5x=-420\)

\(\implies x=-84\)

~ Hok tốt a~

ai nua cac ban

ban nao biet thi minh h

1.  Trả lời: 108

2. Trả lời: 1103

3. Trả lời:107

4. Trả lời: 1107

5. Trả lời: 11106

6. Trả lời: 111915

XIN LỖI MÌNH NHÂM CÂU CUỐI PHẢI LÀ 111105

ủa dễ mà tự làm đê

1.

7/15:(1/2-9/10xX)-1/6=13/6

=>7/15:(1/2-9/10xX)=13/6+1/6

=>7/16:(1/2-9/10xX)=7/3

=>1/2-9/10xX=7/16:7/3

=>1/2-9/10xX=3/16

=>9/10xX=1/2-3/16

=>9/10xX=5/16

=>X=5/16:9/10

=>X=25/72

Các bạn ơi giúp mình đi , minh đang cần gấp

\(-3x\left(x+2\right)^2+\left(x+3\right)\left(x-1\right)\left(x+1\right)-\left(2x-3\right)^2\)

\(=-3x\left(x^2+4x+4\right)+\left(x+3\right)\left(x^2-1\right)-\left(4x^2-12x+9\right)\)

\(=-3x^3-12x^2-12x+x^3-x+3x^2-3-4x^2+12x-9\)

\(=-2x^3-13x^2-x-12\)

gsyfdyfbfsyf

bạn thi violympic à kết quả là -166

giúp mình với

C

4/5<4/4=1<4/3