4x + 5y = -7 -2x - 3y = 3 /*2 4x + 5y = -7 -4x - 6y = 6 ----------------------- 4x - 4x + 5y - 6y = -7 + 6 -y = -1 y = 1 4x + 5 * 1 = -7 4x = -7 - 5 4x = -12 /:4 x = -3 b) 2x + y - 4 = 3x - 3y 4x + 4y = 7x + y - 6 2x - 3x + 3y + y = 4 4x - 7x + 4y - y = -6 -x + 4y = 4 -3x + 3y = -6 /:(-3) -x + 4y = 4 x - y = 2 -------------------- -x + x + 4y - y = 4 + 2 3y = 5 /:3 y = 5/3 -x + 4y = 4 -x + 4 * 5/3 = 4 -x + 20/3 = 4 -x = 12/3 - 20/3 -x = -8/3 x = 8/3
a) [latex]left { {{4x+5y=1-8} atop {-2x-3y=6-3}} ight[/latex] [latex]left { {{4x+5y=-7} atop {-2x-3y=3 / *2}} ight[/latex] [latex]left { {{4x+5y=-7} atop {-4x-6y=6}} ight[/latex] [latex]left { {{-y=-1/:(-1)} atop {3-2x=3y+6}} ight[/latex] [latex]left { {{y=1} atop {-2x=3*1+6-3}} ight[/latex] [latex]left { {{y=1} atop {-2x=6 / :(-2)}} ight[/latex] [latex]left { {{y=1} atop {x=-3}} ight[/latex] A drugiego nie umiem :/ Sorki
