Respuesta :

ma5007482

Step-by-step explanation:

16)(a²-b)÷6

subtitute a and b above:

={(5)²-1}÷6

=(25-1)÷6

=24÷6

=4

18)y-(4-x-y÷2)

subtitute x and y above:

=2-(4-3-2÷2)

=2-(4-3-1)

=2-(4-4)

=2-0

=2

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