Saturday

August 2, 2014

August 2, 2014

Posted by **Jayden Haddy** on Saturday, August 10, 2013 at 11:35pm.

1) Express y in the form of a x(square) + bx +c =0

2) If -3/4 is a root of y, find the value of k

I don't really understand why the answer is like that. Can you explain?

(x^2+3x+1)/(2x^2-5x+2) = k

x^2+3x+1 = 2kx^2 - 10kx+2k

(1-2k)x^2 + (3+10k)x + (1-2k) = 0

since -3/4 is a root,

(1-2k)(9/16) + (3+10k)(-3/4) + (1-2k) = 0

-1/16 (170k+11) = 0

k = -11/170

- maths -
**Bosnian**, Sunday, August 11, 2013 at 6:07am( x ^ 2 + 3 x + 1 ) / ( 2 x ^ 2 - 5 x + 2 ) = k Multiply both sides by 2 x ^ 2 - 5 x + 2

x ^ 2 + 3 x + 1 = k ( 2 x ^ 2 - 5 x + 2 )

x ^ 2 + 3 x + 1 = 2 k x ^ 2 - 5 k x + 2 k

x ^ 2 + 3 x + 1 - 2 k x ^ 2 + 5 k x - 2 k = 0

( 1 - 2 k ) x ^ 2 + ( 3 + 5 k ) x + 1 - 2 k = 0

y = ( 1 - 2 k ) x ^ 2 + ( 3 + 5 k ) x + 1 - 2 k = 0

Now we try to find k

We now :

for x = - 3 / 4 , y = 0

0 = ( 1 - 2 k ) x ^ 2 + ( 3 + 5 k ) x + 1 - 2 k

( 1 - 2 k ) x ^ 2 + ( 3 + 5 k ) x + 1 = 0

( 1 - 2 k ) * ( - 3 / 4 ) ^ 2 + ( 3 + 5 k ) * ( - 3 / 4 ) + 1 - 2 k = 0

( 1 - 2 k ) * 9 / 16 + ( 3 + 5 k ) * ( - 3 / 4 ) + 1 - 2 k = 0 Multiply both sides by 16

( 1 - 2 k ) * 9 * 16 / 16 + ( 3 + 5 k ) * ( - 3 / 4 ) * 16 + 1 * 16 - 2 k * 16 = 0

( 1 - 2 k ) * 9 + ( 3 + 5 k ) * ( - 3 / 4 ) * 4 * 4 + 16 - 32 k = 0

( 1 - 2 k ) * 9 + ( 3 + 5 k ) * ( - 3 ) * 4 + 16 - 32 k = 0

( 1 - 2 k ) * 9 + ( 3 + 5 k ) * ( - 12 ) + 16 - 32 k = 0

1 * 9 - 2 k * 9 + 3 * ( - 12 ) + 5 k * ( - 12 ) + 16 - 32 k = 0

9 - 18 k - 36 - 60 k + 16 - 32 k = 0

- 110 k - 11 = 0

- 110 k = 11 Divide both sides by - 100

k = 11 / - 110

k = - 1 / 10

- maths -
**Bosnian**, Sunday, August 11, 2013 at 6:42amCorrection:

- 110 k = 11 Divide both sides by - 110

k = 11 / - 110

k = - 1 / 10

**Related Questions**

maths - Let ( x(square)+ 3x +1) over (2 x(square) -5x+2) = k ----------be y 1) ...

maths - Consider the equation x(square) + 4px + 2q = 0 where p and q are real ...

Math PLEASE HELP ASAP - -PLEASE INCLUDE SOLUTIONS AND EXPLAIN HOW YOU DID IT ...

Algebra - Express the following in simplest radical form. All variables ...

geometry - If the perimeter of a particular square is 2011 inches, what is the ...

Advanced Algebra - I some problems that I need help with please. Add or subtact ...

Year 11 maths - My teacher said If x-2(square root xy)=9-4(square root 2) so ...

Math simplifying mixed radicals - Please help me simplify these following mixed ...

Math - A square and an equilateral triangle have equal perimeters. The area of ...

MATH - Which expression is a polynomial???? A: 11 0ver the square root of x B: ...