Pleaseeee help me!!!1

Question

First i dont know how to put ______ on between  them so i just put "/  instead. So its all about rational equation.

a) 16n/45 x 63/12n^2    or

  16n              63

______ x _______

   45            12n^2

 

b) 21c^2[c-5]     18c + 9

    _______ x _______

   7c[2c+1]          3c

 

  or 21c^2[c-5] / 7c[2c+1] x 18c + 9 / 3c

Answer 1

(a)

Now write 16 in factor form 16 = 4*4 .

Write 63 in factor form 63 = 9*7 .

Write 45 in factor form 45 = 9*5 .

Write 12 in factor form 12 = 4*3 .

Now cancel  common terms .

So the answer is 28/15n .

Answer 2

(b)

Now write 21 in factor form 21 = 7*3 .

Take out common factor 9 in 18c + 9 = 9(2c+1) .

Write 9 in factor form 9 = 3*3 

Now cancel  common terms .

 = 9(c -5)

So the answer is 9(c -5) .