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WAEC 2022 · Paper 1 · Q10

If a=3a = 3 and b=−7b = -7, find the value of 5b+(a+b)2(a−b)2\dfrac{5b + (a + b)^2}{(a - b)^2}.

Worked solution (try it first)
  1. Put in a=3a = 3 and b=−7b = -7.
  2. The top is 5(−7)+(3−7)2=−35+165(-7) + (3 - 7)^2 = -35 + 16, which is −19-19.
  3. The bottom is (3−(−7))2=102=100(3 - (-7))^2 = 10^2 = 100.
  4. So the value is −19100=−0.19\dfrac{-19}{100} = -0.19, option C.

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