Toán Lớp 9: Giải hệ P/T
$\begin{cases} x+y=720\\\dfrac{115}{100}x+ \dfrac{112}{100}y = 819 \end{cases}$
Leave a reply
Register Now
Login
Lost Password
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Toán Lớp 9: Giải hệ P/T
$\begin{cases} x+y=720\\\dfrac{115}{100}x+ \dfrac{112}{100}y = 819 \end{cases}$
Comments ( 1 )
{(x+y=720),(\frac{115}{100}x+\frac{112}{100}y=819):}
⇔{(x+y=720),(\frac{1}{100}(115x+112y)=819):}
⇔{(x+y=720),(115x+112y=81900):}
⇔{(112x+112y=80640),(115x+112y=81900):}
⇔{(3x=1260),(115x+112y=81900):}
⇔{(x=420),(115.420+112y=81900):}
⇔{(x=420),(y=300):}
Vậy hệ ptr đã cho có nghiệm(x;y)=(420;300)