Find MN. See image below.

Step-by-step explanation:

Tangents from the point outside the circle are equal

NL = JL  

NM + ML =JK + KL

2x - 7 + 9 = 8 + 10  

     2x + 2 = 18      {Subtract 2 from both sides}

           2x = 18 - 2

          2x  = 16   {Divide both sides by 2}

             x = 16/2

x = 8

MN = 2*8 - 7 = 16 - 7 = 9

MN = 9

step-by-step explanation:

answers available in this download

(pearson%2c%25202012)%2520bbs.pdf& usg=aovvaw1obmtxnfghfgxhx0urh_je

y= 2x+7

changed to y= 5x +7

as slope is increased from 2 to 5

therefore it would be less steeper

so, option d) is correct