Question 927946: solve the system by the method of elimination
12x+42y= -17
30x-18y=19
Found 3 solutions by TimothyLamb, brysca, MathTherapy:
Answer by TimothyLamb(4379)   (Show Source):
You can put this solution on YOUR website! 12x+42y= -17
30x-18y=19
---
put the system of linear equations into standard form
---
12x+42y= -17
30x-18y=19
---
copy and paste the above standard form linear equations in to this solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
---
solution:
x = 0.33333333
y = -0.5
---
by elimination:
---
18(12x + 42y = -17)
42(30x - 18y = 19)
---
18*12x + 18*42y = 18*(-17)
42*30x - 42*18y = 42*19
---
add the two equations:
---
18*12x + 42*30x = 18*(-17) + 42*19
(18*12 + 42*30)x = 18*(-17) + 42*19
x = (18*(-17) + 42*19) / (18*12 + 42*30)
x = 0.333333333333
---
12*(0.333333333333) + 42y = -17
y = (-17 - 12*(0.333333333333)) / 42
y = -0.5
---
solution by elimination::
x = 0.33333333
y = -0.5
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php
Answer by brysca(112)  (Show Source):
Answer by MathTherapy(10555)  (Show Source):
You can put this solution on YOUR website!
solve the system by the method of elimination
12x+42y= -17
30x-18y=19
12x + 42y = - 17 -------- eq (i)
30x - 18y = 19 --------- eq (ii)
60x + 210y = - 85 -------- Multiplying eq (i) by 5 ------- eq (iii)
- 60x + 36y = - 38 -------- Multiplying eq (ii) by - 2 ---- eq (iv)
246y = - 123 -------- Adding eqs (iii) & (iv)
y =  , or 
12x + 42(- .5) = - 17 -------- Substituting - .5 for y in eq (i)
12x - 21 = - 17
12x = - 17 + 21
12x = 4
x =  , or 
You can do the check!!
===================
Send comments, “thank-yous,” and inquiries to “D” at MathMadEzy@aol.com.
Further help is available, online or in-person, for a fee, obviously.
For FREE info and answers to questions about the ASVAB exam, the NYS 3 – 8 city/state wide exams,GENERAL
MATH and HOMEWORK QUESTIONS, or MATH QUESTIONS related to the Regents Integrated Algebra,
Regents Geometry, Regents Algebra 2/Trigonometry, SHSAT, COOP/HSPT/TACHS, PSAT, SAT, ACT, SSAT/ISEE,
GRE, CLEP, and the TASC/GED, you can visit: http://asvabstudyzone.freeforums.net/.
|
|
|
