Question

if a2 + b2 = 74 and ab= 35 then find a+b​

Answer 1

Step-by-step explanation:

${(a + b)}^{2} = {a}^{2} + {b}^{2} + 2ab$

$(a + b) = \sqrt{ {a}^{2 } + {b}^{2} + 2ab}$

a+b=

$(a + b) = \sqrt{74 + 2(35)}$

a+b=√144

a+b=+12

Answer 2

Solution :

• a² + b² = 74
• ab = 35
• a + b = ❓

we know that

$\boldsymbol \green{ {a}^{2} + {b}^{2} + 2ab = (a + b {)}^{2} }$

$\boldsymbol{›› \: a + b = \sqrt{ {a}^{2} + {b}^{2} + 2ab } } \: ....(1)$

• Substituting values of a² + b² , ab in (1)

$\boldsymbol{›› \: a + b = \sqrt{74 + 2 \times 35} } \\ \\ \boldsymbol{›› \:a + b = \sqrt{74 + 70} } \\ \\ \boldsymbol{›› \: a + b = \sqrt{144} } \\ \\ \boldsymbol{›› \:a + b = \pm12 }$

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