Question

Люди!! Хелпп!!5.79,5.80

Answer 1

$5.79)quad left { {{7^{x+1}cdot 2^{y}=4} atop {y-x=3}} right. ; left { {{7^{x}cdot 7cdot 2^{x}cdot 2^3=4} atop {y=x+3}} right. ; left { {{14^{x}=frac{1}{14}} atop {y=x+3}} right. \\ left { {{14^{x}=14^{-1}} atop {y=x+3}} right. ; left { {{x=-1} atop {y=2}} right.$

$5.80)quad left { {{(frac{1}{3})^{x}cdot 5^{y}=75} atop {x+y=1}} right. ; left { {{3^{-x}cdot 5cdot 5^{-x}=3cdot 5^2} atop {y=1-x}} right. ; left { {{15^{-x}=15} atop {y=1-x}} right. \\ left { {{-x=1} atop {y=1-x}} right. ; left { {{x=-1} atop {y=2}} right.$