[latex] \left \{ {{2x+3 (x+y)=11.} \atop {7 (x+3y)-6x=-59.}} \right. [/latex]

Question

[latex] \left \{ {{2x+3 (x+y)=11.} \atop {7 (x+3y)-6x=-59.}} \right. [/latex]

Математика

Гость

Ответ(ы) на вопрос:

Accepted Answer

2х+3(х+у)=11 7(х+3у)-6х=-59 -- 2х+3х+3у=11 7х+21у-6х=-59 -- 5х+3у=11 х+21у=-59 -- 5х+3у=11 х=-59-21у -- 5(-59-21у)+3у=11 х=-59-21у -- -295-105у+3у=11 х=-59-21у -- -102у=306 х=-59-21у -- у=306÷(-102) х=-59-21у -- у=-3 х=-59-21×(-3) -- у=-3 х=-59+63 -- у=-3 х=4