Question

ayúdenme porfa lo necesito​

Answer 1

Explicación paso a paso:

$a = 2b \\ a + b = 12 \\ 2b + b = 12 \\ 3b = 12 \\ b = \frac{12}{3} \\ b = 4 \\ a + b = 12 \\ a + 4 = 12 \\ a = 12 - 4 = 8 \\ a - b = 8 - 4 = 4$