Respuesta :

Answer & Step-by-step explanation:

2a - b : 2a + b = 1 : 2

2a - b = 1

-                         Elimination

2a + b = 2

-b - (b) = -1

-2b = -1

b = 0.5

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2a + b = 2           Substitution

2a + 0.5 = 2

2a = 1.5

a = 0.75

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a:b

0.75 : 0.5

or

3/4 : 1/2

Hope this helps!!!