Using the addition method how can I solve this system of equations?

Question

4x + 3y = -2

3x + 2y = -3

Can you show me what other method besides substitution can I use for this then??

Answer 1

You want either the x's or the y's to cancel. It doesn't matter which one. In some cases, one variable may be easier than the other, but that is not the case here.
To cancel the x's you need the coefficients to have the same numerical value but opposite sign.
The coefficients of the x's are 4 and 3.
The least common multiple(LCM) of 4 and 3 is 12.
4 times 3 is 12, so multiply the first equation by 3
12x + 9y = -6
3 times 4 is 12. Multiply the second equation by -4, so they will have opposite signs.
-12x - 8y = 12
Now add the equations.
12x + 9y = -6
-12x - 8y = 12
y = 6
To find x just replace y with 6 in either equation.
4x + 3(6) = -2
4x + 18 = -2
4x = -20
x = -5
Answer: (-5,6)
To check your answer, replace y with 6 in the other equation. If you get the same x value, then your answer is correct. If you get a different x value, then you made a mistake somewhere.
3x + 2(6) = -3
3x + 12 = -3
3x = -15
x = -5 The x value is the same, so the answer is correct.

Answer 2

4x+3y = -2
3x+2y = -3

-3(4x+3y) = 6
4(3x+2y) = -12

-12x - 9y = 6
12 x + 8y = -12

-y = -6
y = 6


since 4x+3y = -2
4x + 3(6) = -2
4x + 18 = -2
4x = -20
x = - 5

or

4x+3y = -2
3x+2y = -3

-2(4x+3y) = 4
3(3x+2y) = -9

-8x - 6y = 4
9x + 6y = -9

x = 5



since 4x+3y = -2
4(5) + 3y= -2
20+ 3y = -2
3y = 18
y = 6

Answer 3

first you need to multiply the first equation by the number negative 3. Then, multiply the second equation by the number 4.
-12x + -9y = 6

12x + 8y = -12

Eliminate the "x's"

-9y = 6

8y = -12

Then add the y's.

-1y = -6

Multiply both sides by negative one.

y = 6

then put it in the original equation and solve for x.

4x + 3(6) = -2
4x + 18 = -2
-18 -18
4x= - 20
/4 /4
x= -5

Then plug in both numbers in both equations to check your work.

4( -5) + 3(6) = -2
-20 + 18 = -2
-2 = -2

3( -5) + 2(6) = -3
-15 + 12 = -3
-3 = -3
:)

Answer 4

Multiply first equation by utilising -4 -12x +16y = -4 then upload the two EQUATIONS 12x - y = -11 15y = -15 divide the two aspects by utilising 15 y = -a million replace -a million for y to remedy for x 3x - 4(-a million) = a million 3x +4 = a million subtract 4 from the two aspects 3x = -3 divide the two aspects by utilising 3 x = -a million (-a million, -a million)

Answer 5

There is an addition method for simultaneous equations now?

Are you sure you aren't meant to be doing subtraction or substitution?

Answer 6

there is one more...elimination method...
4x + 3y =-2 >this will be your equation one
3x+2y=-3 >equation 2
equation 1 will be multiplied by 2= 8x+6y=-4
equation 2 will be multiplied by 3= 9x+6y=-9
therefore8x+6y=-4
-)-9x-6y=9
--------------------------------
-x =5
x=-5
substitute x to equation 1 or 2 then get y.

Answer 7

Obviously the x and y factors are minus in nature, put your logic to use.

Answer 8

Yea, I don't think you can, but you might be able to reduce them. Good luck with that.

Answer 9

uuuhhhhhh..........i dont think we covered that in school yet......