Cho \(\frac{x+16}{9}\)=\(\frac{y-25}{16}\)=\(\frac{z+9}{25}\)và \(\frac{9-x}{7}\)+\(\frac{11-x}{9}\)= 2.Tìm x+y+z.
Cho \(\frac{x+16}{9}=\frac{y-25}{16}=\frac{z+9}{25}\) và \(\frac{9-x}{7}+\frac{11-x}{9}=2\).Tính x+y+z?
Từ \(\frac{9-x}{7}+\frac{11-x}{9}=2\)
\(=>\frac{9-x}{7}+\frac{11-x}{9}-2=0\)
\(=>\frac{9-x}{7}+\frac{11-x}{9}-1-1=0\)
\(=>\left(\frac{9-x}{7}-1\right)+\left(\frac{11-x}{9}-1\right)=0\)
\(=>\frac{2-x}{7}+\frac{2-x}{9}=0=>\left(2-x\right).\left(\frac{1}{7}+\frac{1}{9}\right)=0\)
Vì \(\frac{1}{7}+\frac{1}{9}\) khác 0=>2-x=0=>x=2
Theo T/c dãy tỉ số=nhau:
\(\frac{x+16}{9}=\frac{y-25}{16}=\frac{z+9}{25}=\frac{x+16+y-25+z+9}{9+16+25}\)\(=\frac{\left(x+y+z\right)+\left(16-25+9\right)}{9+16+25}=\frac{x+y+z}{50}\)
Thay x=2 vào \(\frac{x+16}{9}=>\frac{2+16}{9}=\frac{x+y+z}{50}=>\frac{x+y+z}{50}=2=>x+y+z=100\)
Vậy x+y+z=100
Cho \(\frac{x+16}{9}=\frac{y-25}{16}=\frac{z+9}{25}\)và \(\frac{9-x}{7}+\frac{11-x}{9}=2\),Tính x + y + z
Ta có : \(\frac{9-x}{7}=\frac{11-x}{9}=1+\frac{2-x}{7}+1+\frac{2-x}{9}=2=>\left(2-x\right)\left(\frac{1}{7}+\frac{1}{9}\right)=0=>2-x=0=>x=2\)
Thế vào tìm đc y và z rồi ra x+y+z nha bạn
Cho \(\frac{x+16}{9}=\frac{y-25}{16}=\frac{z+9}{25}\)và\(\frac{9-x}{7}+\frac{11-x}{9}=2\)
Tìm x,y,z
Cho \(A=\frac{x+16}{9}=\frac{y-25}{16}=\frac{z+9}{25}\) và \(\frac{9-x}{7}+\frac{11-x}{9}=2\)
tìm x+y+z
2.CMR C=\(220^{119^{69}}+119^{69^{220}}+69^{220^{119}}\)chia hết cho 102
Tìm x,y,z biết:
Cho \(\frac{x+16}{9}=\frac{y-25}{16}=\frac{z+9}{25}và2x^2-1=15\)
Cho \(\frac{x+16}{9}=\frac{y-25}{16}=\frac{z+9}{25}\) và \(2x^3-1=15\)
Tìm x,y,z.
2x3 - 1 = 15 <=> 2x3 = 16
<=> x3 = 8 = 23
=> x = 2
\(\Leftrightarrow\frac{2+16}{9}=\frac{18}{9}=2\)
\(\Leftrightarrow\frac{y-25}{16}=2\) => y - 25 = 32 => y = 57
\(\Leftrightarrow\frac{z+9}{25}=2\) => z + 9 = 50 => z = 41
Vậy x = 2; y = 57; z = 41
Biết \(\frac{x+16}{9}=\frac{y-25}{16}=\frac{z+9}{25}\) và 2.x3 -1=15. Tính x+y+z
cho \(\frac{x+16}{9}=\frac{y-25}{16}=\frac{z+9}{25}\)và 2x3-1=15
tính x+y+z
Quá đơn giản :
2x3-1 = 15
=> 2x3=16
=> x3 = 8
=> x =2
Thay x vào \(\frac{x+16}{9}\)
=> \(\frac{2+16}{9}=2\)
=> \(2=\frac{y-25}{16}\)
=> y-25 = 32
=> y = 57
=> \(2=\frac{z+9}{25}\)
=> z + 9 = 50
=> ...
Đ/S: ...