Posted by **John** on Wednesday, April 23, 2008 at 9:49pm.

solve for X 30y=x^2-14x+13

- Math -
**Damon**, Wednesday, April 23, 2008 at 9:56pm
x^2 - 14 x + 13 = 30 y

x^2 - 14 x = 30 y - 13

x^2 - 14 x + 49 = 30 y + 36

(x-7)^2 = 30 y + 36

x - 7 = +/- sqrt (30 y + 36)

x = 7 +/- sqrt (30 y + 36)

- Math -
**Damon**, Wednesday, April 23, 2008 at 10:02pm
This is so much harder than your other question that I suspect a typo by the way.

- Math -
**John**, Wednesday, April 23, 2008 at 10:05pm
x^2 - 14 x + 13 = 30 y

x^2 - 14 x = 30 y - 13

x^2 - 14 x + 49 = 30 y + 36 ****

(x-7)^2 = 30 y + 36

x - 7 = +/- sqrt (30 y + 36)

x = 7 +/- sqrt (30 y + 36)

where did you get the 49 or 36

- Math -
**Damon**, Wednesday, April 23, 2008 at 10:10pm
Completing the square

x^2 + a x = something

x^2 + a x + (a/2)^2 = something + (a/2)^2

so

if

x^2 -14 x = something

then

x^2 - 14 x +(14/2)^2 = something + (14/2)^2

or

x^2 - 14 x + 49 = something + 49

(x-7)^2 = something + 49

x - 7 = +/- sqrt (something + 49)

by taking half the second coefficient and squaring it, I get a perfect square.

- Math -
**Damon**, Wednesday, April 23, 2008 at 10:13pm
and 49 - 13 = 36

- Math -
**JOHN**, Wednesday, April 23, 2008 at 10:24pm
why is this not correct

30y = x^2 - 14x + 13

- 13

30y - 13 = x^2 - 14x

_________ ___________

-14 -14

x = sqrt 30y-13

_______

-14

Im really trying to follow your work... This is what I got the first time I tried before i asked...

## Answer this Question

## Related Questions

- Math - why is this not correct 30y = x^2 - 14x + 13 - 13 30y - 13 = x^2 - 14x ...
- Math - 30y = x^2 - 14x + 13 FOR X
- algebra - solve the following equation by clearing fractions show all work want ...
- MATH ALGEBRA - Which of the following coordinates are intercepts of the linear ...
- algebra - solve the following equation by clearing fraction want to know if this...
- math - which equation is equivalent to 5x-2(7x+1)=14x? why? a -9x-2=14x b -9xt1=...
- Algebra2 - The area of a square garden in square feet is 49x^2-14x+1. Find the ...
- Maths - find the equation of the perpendicular bisector of the line joining P(2...
- algebra - Solve 14 - ln(2-x)=0. solve for x -ln(2-x)=-14 ln 1/(2-x)=-14 1=-14(2-...
- Math - Derivatives - Differentiate the given function. Simplify the answer. f(x...

More Related Questions