Question

пожалуйста,методом подстановки(сколько сможете)​

Answer 1

$1); ; left { {{frac{x}{5}=1-frac{y}{15}; |cdot 15} atop {2x-5y=0quad }}right.; ; left { {{3x=15-y} atop {2x=5y}} right. ; left { {{y=15-3xquad } atop {2x=5cdot (15-3x)}} right. ; left { {{y=15-3x} atop {2x=75-15x}} right. ; left { {{y=15-3x} atop {17x=75}} right. \\left { {{y=15-3cdot frac{75}{17}} atop {x=frac{75}{17}}} right. ; left { {{y=frac{30}{17}} atop {x=frac{75}{17}}} right. ; ; to ; ; (frac{75}{17}, ,, frac{30}{17})$

$2); ; left { {{4x-3y=1} atop {frac{2x+1}{6}=frac{9-5y}{8} }} right.; left { {{4x=1+3yqquad ; } atop {8(2x+1)=6(9-5y)}} right.; left { {{4x=1+3yqquad } atop {16x+8=54-30y}} right.; left { {{4x=1+3y; |cdot 2quad } atop {16x=46-30y, |:2}} right. \\left { {{8x=2+6y} atop {8x=23-15y}} right. opminus left { {{4x=1+3y} atop {0=21-21y}} right. ; left { {{4x=1+3cdot 1} atop {y=1}} right. ; left { {{x=1} atop {y=1}} right. ; ; to ; ; ; (1,1)$