# I.- Sistemas de 1er. grado con dos incógnitas

 901. 902. $5x-\:&space;y=\:&space;3$ $3x+5y=31$ $2x+3y=8$ $4x-\;&space;\:&space;y=26$
 903. 904. $11x-10y=14$ $5x-3y=14$ $\;&space;\:&space;5x-\:&space;\;&space;7y=41$ $7x+6y=40$
 905. 906. $\:&space;\;&space;5x+\:&space;7z=43$ $8x+21z=33$ $11x+9z=69$ $6x+35z=177$
 907. 908. $13x-\;&space;9y=17$ $5x-2y=33$ $11x-15y=\;&space;7$ $7x=63$
 909. 910. $x+5y=13$ $3x+2y=33$ $x-\;&space;y=\;&space;7$ $7x+\;&space;y=44$
 911. 912. $x+\;&space;y=19$ $5x+6y=\;&space;2$ $2x-y=\;&space;2$ $7x-2y=54$
 913. 914. $3x+y=10$ $3x-\;&space;y=1$ $x-\;&space;y=-1$ $2x+3y=8$
 915. 916. $2x+25=3y$ $5x+3y=58$ $4x-y=25$ $3x+5y=54$
 917. 918. $12x-7y=71$ $4x+12y=28$ $15x-9y=87$ $5x-\;&space;3y=-1$
 919. 920. $3x+5y=20$ $\bg_black&space;7x-3y=&space;-8$ $7x+4y=39$ $5x-3y=50$
 921. 922. $6(x-3)=7y$ $3(x+2)=10y$ $2x-\;&space;y=30$ $5x-31=3y$
 923. 924. $5x+2y=79$ $3x+5y=20$ $3(x+5)=4y$ $2(x-5y)=0$
 925. 926. $5x=4(y+1)$ $3(8x-23)=-7y$ $21=3(2x-y)$ $21=7(9x-5y)$
 927. 928. $x=2(11-y)$ $x+3y=10(x+6)$ $y-3=5(x-5)$ $x-1=y-9x$
 929. $3(2x-y+5)=7,50(x+1)$ $x+5y=2x+4,50y$
 930. $4x-7=3(x-2+y)$ $18x+15y=2(x-2y-6,50)$
 931. 932. $x+y=12$ $3x-\frac{y}{4}=10$ $\frac{x}{2}+\frac{y}{3}=8$ $x-2y=20$
 933. 934. $\frac{2x}{5}+\frac{3y}{4}=5$ $\frac{3x}{8}-\frac{2y}{5}=5$ $x-y=1$ $\frac{x}{2}+3y=95$
 935. 936. $2x+3y=\frac{43}{12}$ $\frac{x}{7}+\frac{y}{6}=10$ $\frac{x}{2}+\frac{y}{3}=\frac{7}{12}$ $x-y=44$
 937. 938. $4x-3y=24$ $\frac{x}{3}-\frac{y}{2}=4$ $\frac{x}{5}=\frac{y}{4}$ $2x+2y=44$
 939. 940. $\frac{x}{y}=\frac{3}{4}$ $3x-2y=12$ $5x-4y=-3$ $\frac{5x}{8}+\frac{2y}{3}=9$
 941. 942. $\bg_black&space;\frac{x}{7}+\frac{y}{9}=&space;\frac{22}{21}$ $2x=3y$ $\frac{x}{8}-\frac{y}{12}=\frac{3}{8}$ $\frac{2x}{3}=\frac{4y}{5}+2$
 943. 944. $3x+\frac{7y}{9}=19$ $5x+\frac{y}{5}=23$ $y-6=\frac{3x}{4}$ $5y-\frac{31x}{4}=44$
 945. $\frac{x}{2}+\frac{y}{3}=10$ $\frac{5x}{7}-\frac{2y}{9}=8$
 946. $\frac{x+y}{2}-\frac{x-y}{3}=11$ $x=\frac{2y}{5}+12$
 947. 948. $\frac{x+1}{y}=\frac{1}{4}$ $\frac{2x}{3}-\frac{5y}{4}=-3$ $\frac{x}{y+1}=\frac{1}{5}$ $\frac{x+y}{x-y}=-7$
 949. $5(x-y)=4x-1$ $\frac{7}{2}(x-2y-3)=\frac{1}{4}(15x+8y)$
 950. $\frac{4x+7}{y}=29$ $\frac{5x}{2x-3y}=3+\frac{7}{31}$

Soluciones