5. Chrystelle mange sa collation de bébés carottes. Elle donne la moitié de 3 dizaines à son ami Denis. Elle en mange 3 fois plus
que Denis. À la fin de la récréation, il lui en reste 23 unités.
(Combien avait-elle de bébés carottes au départh?

Heptagon is the correct ans

The answer is 9.7 cm

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.