1)a) {3x-9y=12 *4 {12x-36y=48
{4x+2y=16 | *(-3) {-12x-6y=-48; -42y=0; y=0; 3x-9*0=12; x=4
Ответ. (4;0)
{ (√5)^(2x+y) =√((1/5)*5); {5^(0,5*(2x+y))=√1; {5^(0,5*(2x+y))=5^0
{(1/5)^x *5^y =5^3; {5^(-x) *5^y =5^3; {5^(-x+y)=5^3
{0,5*(2x+y)=0; {2x+3+x=0; {3x=-3; {x=-1
{ -x+y =3; {y=3+x; {y=x+3; {y=2 Ответ. (-1;2)
2) {x1 +x2≤16; {6x1≤31; {x1≤5(1/6); {0≤x1≤5 (1/6)
{5x1 -x2 ≤15 {4x1 - x2 ≤-12; {-5x2 ≤-20; {x2≥4 x∈[4;5(1/6) ]
{4x1 -x2≤-12; {-4x1 -4x2≤-8; {x1≥0; x2≥0 --------------------
{x1 +x2 ≥2 x1≥0; x2≥0
{x1≥0; x2≥0
{