SOLUTION: through linear substitution please help find answer to: y=-3x-18 5x-2y=-8 and through linear elimination please help find answer to: 3x-2y=1 -6x+4y=-2 Thank you, Lee

Question 12161: through linear substitution please help find answer to:
y=-3x-18
5x-2y=-8
and through linear elimination please help find answer to:
3x-2y=1
-6x+4y=-2
Thank you,
Lee from NC
Answer by rapaljer(4671) (Show Source): You can put this solution on YOUR website!
Substitution method:

y=-3x-18
5x-2y=-8

Second equation:
5x - 2(______) = -8
5x - 2(-3x-18)=-8
5x + 6x + 36 = -8
11x + 36 = -8
11x + 36-36 = -8 - 36
11x = -44
x= -4

Substitute back into the first equation to find y:
y= -3x - 18
y= -3(-4) - 18
y=12 - 18 = -6

Substitute both answers into the second equation for a check:
5x-2y= -8
5(-4)-2(-6)= -8
-20+12 = -8
It checks!

Elimination method:

3x-2y=1
-6x+4y=-2
In order to eliminate the y term, multiply the first equation by 2 and add the second equation.
6x-4y = 2
-6x + 4y = -2

Adding the equations together you get 0=0 which is always true. This means that they are indeed the same line, and the solution is the entire line.

R^2 at SCC

RELATED QUESTIONS
please help me solve this. its linear systems by substitution 3x+2y=5... (answered by mananth)

Please help me to find the x intercept and y intercept of this linear equation 3x +... (answered by solver91311)

-5x+2y=-10 3x-6y=-18 what would be the steps and the answer to this problem in... (answered by stanbon)

please help me understand the difference between substitution and elimination method. use (answered by Theo,algebrapro18)

These 3 problems are causing me stress as I can barely understand the elimination and... (answered by Theo)

please help with graphing and linear equations question 1) what is the slope of..... (answered by solver91311,MathLover1)

Can you please help me solve this linear equation using substitution -3x+6y = 9 5x-2y (answered by MathLover1)

2. For the systems of linear equations in questions 1-3 - Determine how many solutions... (answered by josmiceli)

Could someone help me solve these problems step by step? 18.) y=3.5x -1 Graph the linear (answered by checkley77)