Respuesta :

Answer:

a) 4x

b)

[tex]8 \cdot \: 9y - 8 \cdot2[/tex]

and

8(9y-2)

Step-by-step explanation:

For part a) We want to simplify:

[tex]x + x + x + x[/tex]

This gives us

[tex]4x[/tex]

For part b), we factorize

[tex]72y - 16[/tex]

There is a common factor of 8

[tex]72y - 16 = 8 \times 9y - 8 \times 2[/tex]

This also equals:

[tex]72y - 16 = 8 (9y - 2)[/tex]