Tìm y
y + y x 1/3 : 2/9 + y : 2/7 = 25
y : 4 + y : 3 + y = 5/6
y x 5 + y x 3 + y + y =50
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
20 tháng 8 2020
1) Ta có: \(x^2-2x-9y^2+6y\)
\(=x^2-2x+1-9y^2+6y-1\)
\(=\left(x-1\right)^2-\left(3y-1\right)^2\)
\(=\left(x-1-3y+1\right)\left(x-1+3y-1\right)\)
\(=\left(x-3y\right)\left(x+3y-2\right)\)
3) Ta có: \(x^2-9-4xy+4y^2\)
\(=\left(x-2y\right)^2-3^2\)
\(=\left(x-2y-3\right)\left(x-2y+3\right)\)
4) Ta có: \(\left(a+b\right)^2-\left(a-b\right)^2\)
\(=\left(a+b-a+b\right)\left(a+b+a-b\right)\)
\(=2b\cdot2a=4ab\)
5) Ta có: \(\left(x+y\right)^3-3xy\left(x+y\right)\)
\(=\left(x+y\right)\left[\left(x+y\right)^2-3xy\right]\)
\(=\left(x+y\right)\left(x^2+2xy+y^2-3xy\right)\)
\(=\left(x+y\right)\left(x^2-xy+y^2\right)\)
6) Ta có: \(\left(x-y\right)^3+3xy\left(x-y\right)\)
\(=\left(x-y\right)\left[\left(x-y\right)^2+3xy\right]\)
\(=\left(x-y\right)\left(x^2-2xy+y^2+3xy\right)\)
\(=\left(x-y\right)\left(x^2+xy+y^2\right)\)
7) Ta có: \(4x^2-12x-46\)
\(=\left(2x\right)^2-2\cdot2x\cdot3+9-55\)
\(=\left(2x-3\right)^2-55\)
\(=\left(2x-3-\sqrt{55}\right)\left(2x-3+\sqrt{55}\right)\)
24 tháng 6 2019
\(a,5\frac{1}{4}+3,25-50\%+y=15,25\)
\(\Leftrightarrow5,25+3,25-\frac{50}{100}+y=15,25\)
\(\Leftrightarrow5,25+3,25-0,5+y=15,25\)
\(\Leftrightarrow8+y=15,25\)
\(\Leftrightarrow y=15,25-8=7,25\)
24 tháng 6 2019
\(b,(y-3):2=2010\)
\(\Leftrightarrow y-3=4020\)
\(\Leftrightarrow y=4023\)
\(y+y.\frac{1}{3}.\frac{9}{2}+y.\frac{7}{2}=25\)
\(y+y.6+y.\frac{7}{2}=25\)
\(y.\left(1+6+\frac{7}{2}\right)=25\)
\(y.\frac{21}{2}=25\)
\(y=25:\frac{21}{2}\)
\(y=25.\frac{2}{21}\)
\(y=\frac{50}{21}\)
\(y.5+y.3+y+y=50\)
\(y.\left(5+3+1+1\right)=50\)
\(y.10=50\)
\(y=5\)