Question

If a+b=7 and ab=10 find a-b

Answer 1

Hey friend. .!! here's your answer
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$a + b = 7 - - - - - - -1 \\ \\ \\ ab = 10 - - - - - - - - 2$

Frome equation 1

a = 7 - b________ 3

Put the value of eq 3 in eq . 2

(7 - b) b = 10

${b}^{2} - 7b = 10$

Now , Factorise

$- ( {b}^{2} - 7b + 10) = 0\\ \\ - ( { {b}^{2} - 5b - 2b } + 10) = 0 \\ \\ - ( b(b -5 ) - 2(b - 5) = 0 \\ \\ - ((b - 2)(b - 5))$

So b = 2 or 5

Put the value of b in eq 3

a = 7 - 2
a = 5

value of a = 5 and b = 2
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#Hope its help