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Problem 1.

-4x+8y= 1
3x-6y= 1


Problem 2.

2x+5y= 15
-6x-15y= -45

2006-07-18 04:55:02 · 10 answers · asked by Brandon ツ 3 in Science & Mathematics Mathematics

Look at my record, I do will select an answer asap.

2006-07-18 04:55:57 · update #1

10 answers

-4x + 8y = 1
3x - 6y = 1

-4x + 8y = 1
8y = 4x + 1
y = (1/2)x + (1/8)

3x - 6y = 1
-6y = -3x + 1
y = (1/2)x - (1/6)

Same slope, different y-intercepts

ANS : No Solution

----------------------------------

2x + 5y = 15
-6x - 15y = -45

2x + 5y = 15
5y = -2x + 15
y = (-2/5)x + 3

-6x - 15y = -45
-15y = 6x - 45
y = (-6/15)x + 3
y = (-2/5)x + 3

Since they have the same slope and same y-intercept

ANS : Infinite Solutions

2006-07-18 07:13:53 · answer #1 · answered by Sherman81 6 · 4 0

There are no solutions to the first problem:

[-4x+8y=1] * 3 => -12x + 24y =3
[3x-6y=1] * 4 => 12x - 18y = 3

adding the equations yields: 0 + 6y = 0 so y is 0 but there is no number that when multiplied by -4 and 3 yields 1

[2x + 5y=15] * 3 => 6x + 15y = 45
-6x - 15y =-45 =>-6x - 15y = -45

adding the equations yields 0 = 0, but if x is 0, y = 3

2006-07-18 12:12:22 · answer #2 · answered by Wytecyde 1 · 0 0

For problem 2: they are the equation really. multiply the top by -3 and you have the same line. so the solution is the line of the equation.

problem 1:
add the two equations: -x + 2y = 2 ==> x=2(y-1)
plug into bot. eqn: 3(2(y-1))-6y=1 ==> 1 = 1
thus there's no intersection of the two lines, they are parallel lines

2006-07-18 12:07:53 · answer #3 · answered by cw 3 · 0 0

Note that a linear equation represents a straight line in the x-y space.

First one:
they are parallel lines: so no solution

Second one:
they are coincident: so infinite solutions (all points lying on the line 2x+5y=15)

2006-07-18 12:03:27 · answer #4 · answered by robo 1 · 0 0

Empty set for the first problem. They work out to having the same slope but different y-intercepts.
y=1/2x+1/8
y=1/2x-1/6

Second system works out to infinity. They work out to being the same line with formula y=2/5x+3

2006-07-18 12:09:39 · answer #5 · answered by carpetao 3 · 0 0

Both sets of equations are underdetermined.

In problem 2 eqaution 2 equals equation one multiplied by -3

In problem one equation two equals equation one multiplied
by -3/4.

You need two linearly independent equations to solve for x and Y.

You do not have them in these examples

2006-07-18 12:07:33 · answer #6 · answered by gilbraltor 1 · 0 0

Skywalker, simultaneous as well as quadratic equations are lots of fun. Pay closer attention in class. You'll enjoy them.

2006-07-18 12:32:14 · answer #7 · answered by Njihem 2 · 0 0

They are parrallel lines. They meet at infinity. So x= y = infinity is one mathematical solution.

2006-07-18 12:37:07 · answer #8 · answered by Dr M 5 · 0 0

try r

2006-07-18 12:02:44 · answer #9 · answered by sahi 2 · 0 0

Please do your OWN homework!

2006-07-18 12:29:10 · answer #10 · answered by ? 3 · 0 0

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