Question 5353: I need to solve by factoring: m^2-2m-63=0
Thanks for your help. Found 3 solutions by guapa, Abbey, jainenderkapoor:Answer by guapa(62) (Show Source):
You can put this solution on YOUR website! m²- 2m - 63 = 0
You need to find 2 numbers whose sum is -2 and whose product is -63. A way to do that is to express 63 in its prime factors. 3*3*7. Now use these factors in different combination and you´ll find the 2 numbers you need. In this case the numbers are 9 (3*3) and 7(7). So, -9+7= -2 and -9*7= -63.
Now you can solve the equation as follows:
m²-9m +7m -63=0 Now you need to factor
m(m-9)+7(m-9)=0
(m-9)(m+7)=0
m-9=0, m=9
m+7=0, m= -7
The solution set is {-7,9}
You can put this solution on YOUR website!
I chose -9 and 7 because when multiplied together they = -63 and when added together they = -2
Then set each = 0
m-9=0
Add 9 to both sides to get
m=9
or m+7=0
subtract 7 from both sides:
m=-7
so your solution is m=9,-7
You can put this solution on YOUR website! Hi.
To solve the polynomial compare it with ax^2 + b x + c
We get a = 1, b = -2, c = -63
Sum = b = -2
Product = a * c = 1 * -63 = -63
Now we have to find two numbers such that there product is -63 and their sum is -2
Can you find the same?
Yes --- -63 can be broken up into two parts -9 and +7
The product of the numbers -9 and 7 is -63 and the sum is -2
So we get
m^2 - 2m - 63
m^2 - 9m + 7m - 63
m (m - 9) + 7(m - 9) We have taken m common from first two terms and
7 common from the last two terms
(m - 9) (m +7) (By taking out (m-9) common
These are the required factors.
HOPE THIS IS CLEAR TO YOU. IN CASE YOU HAVE ANY OTHER DOUBT YOU MAY CONTACT ME ON kapoorjai1@rediffmail.com ------- I AM AVAILABLE FOR ONLINE TUTORING.
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