Răspuns:
Explicație pas cu pas:
f:R → R ; f(x) = ax + b
A (5; 6) şi B (5/3; 4)
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f(5) = 6 => 5a+b = 6
f(5/3) = 4 => 5a/3 + ³⁾b = ³⁾4 => 5a+3b = 12
5a+b = 6
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2b = 6 => b = 3
a = (6-b):5 = (6-3):5 => a = 3/5
f(x) = 3x/5 + 3 = (3x+15)/5
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∩Ox <=> f(x) = 0 => (3x+15)/5 = 0 => 3x = -15 => x = -5 =>
C(-5 ; 0)
∩Oy <=> x = 0 => f(0) = 15/5 = 3 => D(0 ; 3)
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Aria ΔCOD = (CO·DO):2 = 5·3:2 = 15:2 = 7,5 u.m.²
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