One number is 9 more than another number. If the product of the two numbers is -20, how do you find both numbers?

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One number is 9 more than another number. If the product of the two numbers is -20, how do you find both numbers?

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Answer 1 · 2017-01-10T05:37:11

One number be $- 5$ $-5$ and another number be $4$ $4$
[or]
One number be $- 4$ $-4$ and another number be $5$ $5$

Explanation:

Let the given number be $a$ $a$
Then the next number be $b$ $b$

$b = a + 9$ $b = a+9$

Form the equation -

$a \times (a + 9) = - 20$ $a xx (a+9)=-20$

Solve it for $a$ $a$

$a^{2} + 9 a = - 20$ $a^2+9a=-20$
$a^{2} + 9 a + 20 = 0$ $a^2+9a+20=0$
$a^{2} + 5 a + 4 a + 20 = 0$ $a^2+5a+4a+20=0$
$a (a + 5) + 4 (a + 5) = 0$ $a(a+5)+4(a+5)=0$
$(a + 5) (a + 4) = 0$ $(a+5)(a+4)=0$

$a + 5 = 0$ $a+5=0$
$a = - 5$ $a=-5$
$a + 4 = 0$ $a+4=0$
$a = - 4$ $a=-4$

If $a = - 5$ $a=-5$

$b = a + 9$ $b=a+9$
$b = - 5 + 9 = 4$ $b=-5+9=4$

If $a = - 4$ $a=-4$

$b = a + 9$ $b=a+9$
$b = - 4 + 9 = 5$ $b=-4+9=5$

One number be $- 5$ $-5$ and another number be $4$ $4$
[or]
One number be $- 4$ $-4$ and another number be $5$ $5$

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One number is 9 more than another number. If the product of the two numbers is -20, how do you find both numbers?

1 Answer

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