giúp mình nhé:
3.(2-x)+5.(x-6)=-98
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Ta có: \(\left\lbrace\left\lbrack\left(x^3-17\right)^2-98\right\rbrack^3-6\right\rbrace^5=32\)
=>\(\left\lbrack\left(x^3-17\right)^2-98\right\rbrack^3-6=2\)
=>\(\left\lbrack\left(x^3-17\right)^2-98\right\rbrack^3=2+6=8=2^3\)
=>\(\left(x^3-17\right)^2-98=2\)
=>\(\left(x^3-17\right)^2=100\)
=>\(\left[\begin{array}{l}x^3-17=10\\ x^3-17=-10\end{array}\right.\Rightarrow\left[\begin{array}{l}x^3=27\\ x^3=7\end{array}\right.\Rightarrow\left[\begin{array}{l}x=3\left(nhận\right)\\ x=\sqrt[3]{7}\left(loại\right)\end{array}\right.\)
số cần tìm là :
73/ 98 - 1/6 = 85/147
Đ / S : ......
Nhớ K mik nha
a: \(\frac{52}{17}>\frac{51}{17}=3\)
\(3=\frac{121}{41}>\frac{120}{41}\)
Do đó: \(\frac{52}{17}>\frac{120}{41}\)
b: \(\frac34+\frac14:\left(\frac{7}{12}-\frac16\right)\)
\(=\frac34+\frac14:\left(\frac{7}{12}-\frac{2}{12}\right)\)
\(=\frac34+\frac14:\frac{5}{12}\)
\(=\frac34+\frac14\times\frac{12}{5}=\frac34+\frac35=\frac{15}{20}+\frac{12}{20}=\frac{27}{20}\)
c: \(372,463\cdot998+744,926\)
\(=372,463\cdot998+372,463\cdot2\)
\(=372,463\times\left(998+2\right)=372,463\times1000=372463\)
d: Số số hạng trong dãy số 2;4;6;...;100 là:
\(\left(100-2\right):2+1=98:2+1=49+1=50\) (số)
\(2-4+6-8+10-12+\cdots+98-100+102\)
\(=\left(2-4\right)+\left(6-8\right)+\cdots+\left(98-100\right)+102\)
=(-2)+(-2)+...+(-2)+102
\(=-2\cdot\frac{50}{2}+102=-50+102=52\)
e: (y+112)-113=79
=>y+112-113=79
=>y-1=79
=>y=79+1=80
f: \(\frac34-y=\frac12\)
=>\(y=\frac34-\frac12=\frac14\)
g: \(\left(\frac45-2\times y\right)+\frac16=\frac56\)
=>\(\frac45-2\times y=\frac56-\frac16=\frac46=\frac23\)
=>\(2\times y=\frac45-\frac23=\frac{12}{15}-\frac{10}{15}=\frac{2}{15}\)
=>\(y=\frac{2}{15}:2=\frac{1}{15}\)
h: (y+1)+(y+2)+...+(y+50)=1750
=>50y+(1+2+...+50)=1750
=>\(50y+50\times\frac{51}{2}=1750\)
=>50y+1275=1750
=>50y=1750-1275=475
=>\(y=\frac{475}{50}=9,5\)
đây
3(2−𝑥)+5(𝑥−6)=−983({\color{#c92786}{2-x}})+5(x-6)=-983(−𝑥+2)+5(𝑥−6)=−98\(3\left(2-x\right)+5\left(x-6\right)=-98\\ \Rightarrow6-3x+5x-30=-98\\ \Rightarrow2x-24=-98\\ \Rightarrow2x=-74\\ \Rightarrow x=-37\)