Question

2c + u =9 , 6c + u = 21

Answer 1

Respuesta:

c = 3

u = 3

Explicación paso a paso:

2c + u =9

u = 9 - 2c

---

6c + u = 21

u = 21 - 6c

----

9 - 2c = 21 - 6c

6c -2c = 21 - 9

4c = 12

c = 3

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2(3) + u = 9

6 + u = 9

u = 3