Question 33053: x squared + 12x = 27
Found 2 solutions by priya, sarah_adam:
Answer by priya(51)   (Show Source):
You can put this solution on YOUR website! R U SURE THE EQUATION IS X^2+12X =27,
I think the question should be x^2 +12 x = -27 or
x^2 -12x = 27..
if this right ...herez the answer,
First re-arrange the question in standard equation format..
that is, x^2+12x= -27
as x^2 +12x + 27 =0( when u bring the 27 from the right of the equation to the left u've to change it's sign,hence -27 becomes +27)
then there is a short cut to find the value of x.
if the equation is in the standard form like x^2+ (y)x + c = 0, where y is the co-efficient of x and c is an independent number.,
then
find 2 numbers that gives "c" as product(that is when u multiply the numbers that would give u "c"),and the addition of the same 2 numbers gives the co-efficient of x(here y).
so here ...for 27,the multiples are 1*27,3*9,9*3
now 1. take the first 2 numbers 1 & 27,when u add it does it give the co-efficient of x(here 12) no..
2.so go to the next set of numbers- 3 & 9
when u multiply these 2 numbers,it gives u 27 and when u add it ,it gives u 12(co-efficient of x).
so the numbers are 3 & 9.
so u've to write the numbers as (x+3)(x+9)= 0,therefore the values of x= -3 and -9..
Answer by sarah_adam(201) (Show Source):
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