Réponse :
Bonjour,
Explications étape par étape
1)
[tex]\begin{array}{|c|c|c|c||c|c|c|c|}&Chlo\' e&ain\' e&cadet&&Daphn\' e&ain\' e&cadet\\age\ actuel&a&x+2&x&&b&y+2&y\\age\ a\ venir&50&x+2+50-a&x+50-a&&50&y+2+50-b&y+50-b\\\end{array}\\[/tex]
2)
[tex]\left\{\begin{array}{ccc}50&=&x+2+50-a+x+50-a\\x+50-a&=&2x\\50&=&y+2+50-b+y+50-b\\y+2+50-b&=&2(y+2)\end{array}\right.\\\\\left\{\begin{array}{ccc}a&=&x+26\\a&=&50-x\\b&=&y+26\\b&=&48-y\end{array}\right.\\\\\left\{\begin{array}{ccc}x+26&=&50-x\\y+26&=&48-y\\\end{array}\Right.\\\\[/tex]
[tex]\left\{\begin{array}{ccc}x&=&12\\y&=&11\\\end{array}\right.\\\left\{\begin{array}{ccc}a&=&50-12\\b&=&11+26\\\end{array}\right.\\\left\{\begin{array}{ccc}a&=&38\\b&=&37\\\end{array}\right.\\[/tex]
[tex]Preuve\\\begin{array}{|c|c|c|c||c|c|c|c|}&Chlo\' e&ain\' e&cadet&&Daphn\' e&ain\' e&cadet\\age\ actuel&38&14&12&&37&13&11\\age\ a\ venir&50&26&24&&50&26&24\\\end{array}\\\\[/tex]
3)
Chloé a 38 ans et Daphné 37 ans.
