2){ 2,5 (х - 3у) - 3 = 3х + 0,5{ 3( x + 6y) + 4 = 9y + 19{2,5х - 7,5у - 3х = 0,5 + 3{3x + 18y - 9y = 19 - 4{ - 0.5x - 7.5y = 3.5 | × (-2){ 3x + 9y = 15 | ÷ 3{ x + 15y = - 7{ x + 3y = 5 ⇒ x = 5 - 3yСпособ подстановки:(5 - 3y) + 15y = - 75 + 12y = - 712y = - 7 - 512y = - 12y = -1x = 5 - 3×(-1) = 5+3x = 8Ответ : ( 8 ; - 1) .3){ 1/3 × x + 1/4 × y - 2 =0 | * 12{ 5x - y = 11{4x + 3y - 24 = 0{ y = 5x - 11Способ подстановки:4х + 3(5х - 11) - 24 = 04х + 15х - 33 - 24 = 019х - 57 = 019х = 57х = 57 ÷ 19х = 3у = 5 × 3 - 11 = 15 - 11у = 4Ответ (3 ; 4 ) .