# Math

posted by .

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

• Math -

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 -

This is so much harder than your other question that I suspect a typo by the way.

• Math -

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 -

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 -

and 49 - 13 = 36

• Math -

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...

• Math -

sorry the division signs didn't line up correctly

## Similar Questions

1. ### Algebra2

The area of a square garden in square feet is 49x^2-14x+1. Find the dimensions of the garden in terms of x. x^2=49x^2-14x+1 Then solve for x. 48x^2-14x + 1=0 (8x-1)(6x-1)=0 and solve for two values of x that are possible.
2. ### Math

why is this not correct 30y = x^2 - 14x + 13 - 13 30y - 13 = x^2 - 14x _________ ___________ -14 -14 x = sqrt 30y-13 _______ -14 sorry the division signs didn't line up
3. ### Math

30y = x^2 - 14x + 13 FOR X
4. ### math

which equation is equivalent to 5x-2(7x+1)=14x?
5. ### MATH ALGEBRA

Which of the following coordinates are intercepts of the linear relation 2x- 3y + 30 = 0 ?
6. ### algebra

solve the following equation by clearing fraction want to know if this right -7/3-5/2x=8+2x 6(-7/3)-(5/2)(6)=6(6)+2x(6) 14x-15=48+12x 14x-12x-15=48+14x-14x 2x-15=48 2x-15+15=48+15 2x=-33 2x/2x=-33/2 x=-33/2
7. ### algebra

solve the following equation by clearing fractions show all work want to know if this right -7/3-5/2x=8+2x 6(-2/3)-(5/2x)(6)=6(8)+2x(6) 14x-15=48+12x 14x-12x-15=48+14x-14x 2x-15=48 2x-15+15=48+14x-14x 2x-15=48 2x-15+15=48+15 2x=-33 …
8. ### Maths

find the equation of the perpendicular bisector of the line joining P(2, -4) to Q(-5,1) A. 8y-14x 13=0 B. 8y-14x-13=0 C. 8y 14x-13=0 D. 8y 14x 13=0 Please I need someone to help me with this, with an explanatory workings.
9. ### algebra

Solve 14 - ln(2-x)=0. solve for x -ln(2-x)=-14 ln 1/(2-x)=-14 1=-14(2-x) 1=-28+14x 29=14x 29/14=x not sure where I'm going wrong
10. ### Math Help

What is the sum or difference? A)-7y^5* B)-30y^5 C)-30y^10 D)-7y^10

More Similar Questions