Question 225397
Let  a,,&  b,,,be  legs  of  rt  triangle  with ,,,,a=b+5
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Area  =  1/2 *base* height 
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A= 1/2 *a *b,,,,,subst
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A= 1/2 *(b+5) * b
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A = 1/2 (b^2 +5b)
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A=42 = 1/2 (b^2 +5b)
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84 = b^2 +5b
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0= b^2 +5b -84,,,,,,,,factor
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0= (b-7)(b+12)
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b= 7,  -12 (not  realistic)
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Answer  is  a=b+5= 7+5=12 m ,,,,,,b= 7m
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check,,,,42 = 1/2 *7 *12 = 42 m^2,,,,ok
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