Решите систему уравнений 269

269(1)

$\left \{ {{2*4^x+3*5^y=11} \atop {5*4^x+4*5^y=24}} \right.$
$4^x=a; 5^y=b$
$\left \{ {{2a+3b=11} \atop {5a+4b=24}} \right.$
$\left \{ {{a=5.5-1.5b \atop {5a+4b=24}} \right.$
$\left \{ {{a=5.5-1.5b \atop {5(5.5-1.5b)+4b=24}} \right.$
$\left \{ {{a=5.5-1.5b \atop {27.5-7.5b+4b=24}} \right.$
$\left \{ {{a=5.5-1.5b \atop {-3.5b=24-27.5}} \right.$
$\left \{ {{a=5.5-1.5b \atop {-3.5b=-3.5}} \right.$
$\left \{ {{a=5.5-1.5b \atop {b=1}} \right.$
$\left \{ {{a=5.5-1.5=4 \atop {b=1}} \right.$
$\left \{ {{a=4 \atop {b=1}} \right.$
$\left \{ {{4^x=4 \atop {5^y=1}} \right.$
$\left \{ {{x=1 \atop {y=0}} \right.$