1.[tex] \frac{a}{b} [/tex] =5 => a=5b
[tex] \frac{a-95}{ \frac{b}{2}}[/tex] =5 => [tex] \frac{5b-95}{ \frac{b}{2} } [/tex] =5 => (5b-95)X[tex] \frac{2}{b} [/tex] =5 => [tex] \frac{10b-190}{b} [/tex] =5 => 10b-190= 5b =>5b=190=>B=[tex] \frac{190}{5} [/tex] =38
a=5X38=190
2.S=Stilou
C=Carte
4S+3C=100 |=> C=40-2S
2S+1C=40 |
4S+3(40-2S)=100=> 4S+120-6S=100=> 2S=120-100=> 2S=20=> S=10
40 + 3C=100=> 3C=60=. C=20