2mx-3m-4x+6=2mx-4x-3m+6=2x(m-2)-3(m+2)
{2x-3y=11
{4x+5y=-11
{x=(11+3y)/2
{4(11+3y)/2+5y=-11
(44+12y)/2+5y=-11
22+6y+5y=-11
11y=-11-22
11y=-33
y=-33/11 x=(11+3(-3))/2
y=-3 x=1
1)116/9×1/4+2/3×1/24=24/9+1/36=96+1/36=97/36
2)(9+14/36)×24/23-1=23/36×24/23-1=2/3-1=-1/3
3)5-(30+20+15+12/60)=5-77/60=300-77/60=223/60
4)16/11×11/12-10/9×6/5-54/7=4/3-4/3-54/7=-54/7
5)(24/7×21/8-16)×4/21+176/15=-7×4/21+176/15=-3/4+176/15=659/60
Умножаем второе уравнение на (-2) и складываем с первым