2x+ 3y = 7 x-y=1 x= 1 +y 2( 1+y ) + 3y = 7 x=1+y 2+5y=7/ -2 x=1+y 5y=5 / 5 y=1 x= 2 II. 2x+3y = 13 x-y= -1 / * (-2 ) 2x+3y=13 -2x+2y=2 0+5y=15/ ;5 y=3 y=3 x-y=-1 x-3=-1/ +3 x=2 x=2 y=3
Zad1 [latex] left { {{2x+3y=7} atop {x-y=1}} ight. [/latex] [latex] left { {{2x+3y=7} atop {x=1+y}} ight. [/latex] [latex]2(1+y)+3y=7[/latex] [latex]2+2y+3y=7[/latex] [latex]5y=7-2[/latex] [latex]5y=5 /5[/latex] [latex]y=1[/latex] [latex]x=1+1=2[/latex] [latex] left { {{y=1} atop {x=2}} ight. [/latex] Zad2.[latex] left { {{2x+3y=13} atop {x-y=-1}} ight. [/latex] [latex] left { {{2x+3y=13} atop {x-y=-1}/*-2} ight. [/latex] [latex] left { {{2x+3y=13} atop {-2x+2y-2}} ight. [/latex] [latex]y=15[/latex] [latex]x-15=-1[/latex] [latex]x=-1+15[/latex] [latex]x=14[/latex] Zad3. [latex]a=?[/latex] [latex]r= 4sqrt{3} [/latex] [latex]r= frac{a sqrt{3} }{3} [/latex] [latex]4= frac{a sqrt{3} }{3} /*3[/latex] [latex]12= asqrt{3} /: sqrt{3} [/latex] [latex] frac{12}{ sqrt{3} } =a[/latex] [latex] frac{12}{ sqrt{3} } * [/latex][latex]frac{ sqrt{3} }{ sqrt{3} }[/latex] [latex]= frac{12 sqrt{3} }{3} }[/latex] [latex]= 4sqrt{3} [/latex] [latex]a=4sqrt{3} [/latex]
