tolong no 11 pakai caranya

[tex]11.misalkan \\ 5a + 2b = 4000 | \times 2| \\ 2a + 3b = 2700 | \times 5| \\ = = = = = = = = = = = = \\ 10a + 4b = 8000 \\ 10a + 15b = 13500 \\ = = = = = = = = = = = = - \\ - 11b = - 5500 \\ b = \frac{ - 5500}{ - 11} \\ b = 500 \\ = > 2a + 3b = 2700 \\ 2a + 3(500) = 2700 \\ 2a = 2700 - 1500 \\ 2a = 1200 \\ a = \frac{1200}{2} \\ a = 600 \\ jadi \: harga \: kue \: a + b = 500 + 600 = \\ rp.1100. - [/tex]