Question

Hola Amigos, me pueden ayudar ​

Answer 1

$\left \{ {{5x+7y=-1} \atop {-3x+4y=-24}} \right.\\ x=\frac{-1-7y}{5} \\x=\frac{-24-4y}{-3}\\ x=x\\\frac{-1-7y}{5} = \frac{-24-4y}{-3}\\ (-1-7y)(-3)=(-24-4y)(5)\\3+21y=-120-20y\\21y+20y=-120-3\\41y=-123\\y=-3\\x=\frac{-1-7(-3)}{5} \\x=4$

$\left \{ {{4y+3x=8} \atop {8x-9y=-77}} \right.\\ x=\frac{8-4y}{3} \\x=\frac{-77+9y}{8} \\x=x\\\frac{8-4y}{3} = \frac{-77+9y}{8} \\(8-4y)(8)=(3)(-77+9y)\\64-32y=-231+27y\\-32y-27y=-231-64\\-59y=-295\\y=5\\x=\frac{8-4(5)}{3}\\x=-4$