Question

решите пожалуйста 7 8 9 номера

Answer 1

7.  frac{-5}{a+5}- frac{10}{2(a+5)}- frac{8a}{4(a+5)} =  -frac{2a}{a+5} =  frac{2*5}{19(- frac{5}{19} +5)}= frac{10}{-5+95}= frac{1}{9}
8. ∠ACB = ∠ACD-∠BCD = 180-92 = 88
    ∠BAC = ∠ACB = 88
    ∠ABC = 180 - ∠BAC - ∠ACB = 180-88-88 = 4
     ∠FBC = ∠ABF - ∠ABC = 180 - 4 = 176
9. ∠AOL + ∠BOK = 252
    ∠AOL = ∠BOK
    252/2 = 126
    ∠AOK = ∠KOL - ∠AOL = 180-126 = 54