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DIFFICULT MATH QUESTION!! HELP NEEDED PLEASE!!?
Please solve the following simultaneous equations:
2x = 1 - 3y
3y^2 - x^2 = 2
Please do it step by step for explanation... thank you! :)
3 Answers
- Wile E.Lv 78 years agoFavorite Answer
2x = 1 - 3y
x = 1/2 - 3/2 y
x = 0.5 - 1.5y ......... Eq. 1
3y² - x² = 2 ............. Eq. 2
Sub 0.5 - 1.5y from Eq. 1 for x in Eq. 2:
3y² - (0.5 - 1.5y) = 2
3y² - 0.5 + 1.5y = 2
3y² + 1.5y = 2 + 0.5
3y² + 1.5y = 2.5
3(y² + 0.5y) = 2.5
y² + 0.5y = 2.5 / 3
y² + 0.5y = 0.833
y² + 0.5y + 0.625 = 0.833 + 0.0625
(y + 0.25)² = 0.896
y + 0.25 = √0.896
y + 0.25 = ± 0.947
y = - 0.25 ± 0.947
If y = - 0.25 + 0.947,
y = 0.697
and
x = 0.5 - 1.5(0.697)
x = 0.5 - 8.034
x = - 7.534
One Solution Set (- 7.534, 0.697)
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
If y = - 0.25 - 0.947,
y = - 3.733
and
x = 0.5 - 1.5(- 3.733)
x = 0.5 - (- 5.6)
x = 0.5 + 5.6
x = 6.1
Other Solution (6.1, - 3.733)
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
- ?Lv 58 years ago
2x = 1 - 3y <=== lets call this equation A
3y^2 - x^2 = 2 <=== equation B
first solve for a variable (x or y) for one of the equations.
2x = 1 - 3y <=== divide all terms by 2
x = 1/2 - (3/2)y
Plug in x = 1/2 - (3/2)y into equation B
3y^2 - ((3/2)y)^2 = 2
3y^2 - (9/4)y^2 = 2
(12/4)y^2 - (9/4)y^2 = 2
(3/4)y^2 = 2 <==== multiply both sides by 4/3
y^2 = 2*(4/3)
y^2 = 8/3 <==== square root both sides
y = ±sqrt(8/3)
Plug the value of y into equation A
2x = 1 - 3(sqrt8/3) <=== divide all terms by 2
x = (1/2) - (3/2)(sqrt8/3)
Source(s): http://freemathtutoring.webs.com/ - PeterLv 48 years ago
2x = 1 - 3y
Square both sides of this equation
4x^2 = 1 - 6y + 9y^2
You now have x^2 in terms of y, substitute this into 3y^2 - x^2 = 2 to give a quadratic in y. Solve for y, then find x from the first equation.