What is the answer to this simultaneous equation: 4x + 3y= 5 2x - 5y= 9?

y=-1
x=2


a) 4x + 3y =5
b) 2x -5y =9
2* b) 4x-10y = 18
a -(2b) ) 13y =-13

=> y=-1

if y =-1
x=2

since the coefficients i.e numbers arent the same u multiply one equation by a number that would make 2 coefficients from both the equations to be the same ur aim would be to get the lowest and same coeffiecient so it would be easy
in this case u multiply the equation 2 by -2
so uget
4x+3y=5
-4x+10y=-18
now the coefficient of x are the sameonly signs r different u now solve them using the elimination method its easy for me =)
4x+3y=5
-4x+10y=-18 (+) add them
13y=-13
x is eliminated
so therefore y=-13/13
=-1
now u substitute y=-1 in any equation
lets take the first one
4x+3(-1)=5
4x-3=5
4x=5+3
4x=8
x=2
now u can check
if u want

question a million 2x = 14 x = 7 y = 5 question 2 - 5x - 2y = - 9 2x + 2y = 6-----upload - 3x = - 3 x = a million 2 + 2y = 6 2y = 4 y = 2 x = a million , y = 2 question 3 - 4x - 3y = - 11 4x + 5y = thirteen-----upload 2y = 2 y = a million 4x + 3 = 11 4x = 8 x = 2 x = 2 , y = a million

20x + 15 y = 25
6x - 15 y = 27---------ADD

26 x = 52
x = 2

8 + 3y = 5
3y = - 3
y = - 1

x = 2 , y = - 1

4x+3y=5 2x-5y=9
x= -1 x=7
y= 3 y=1

Solve by using elimination.

4x + 3y = 5 ...... (1)
2x - 5y = 9 ...... (2)

(2) * 2
2x - 5y = 9
2(2x - 5y) = 2(9)
4x - 10y = 18

(1) - (2) * 2
....4x .+ 3y = ..5
‒) 4x - 10y = 18
--------------------------------
...........13y = -13

13y = -13
y = -13/13
y = -1

4x + 3y = 5

Substitute -1 for y.
4x + 3(-1) = 5
4x - 3 = 5
4x = 5 + 3
x = 8/4
x = 2

∴ x = 2, y = -1

4x + 3y= 5 ,,,,,(1)
2x - 5y= 9 ....(2)
Multiply eqn (2) by 2, we get
4x - 10y =18 ....(3)
subtract (3) from (1) we have
4x + 3y - (4x - 10y) = 5 - 18
3y + 10y = - 13
13 y = - 13
y = - 1
Sub y = - 1 in eqn (1) we get
4x +3(- 1) = 5
4x = 5 + 3
x = 8/4
x = 2

So x = 2 any y = -1 (Answer)

4x+3y=5 *5 ----- 1
2x-5y=9 *3 ------2
1; 20x+15y=25
2; 6x-15y=27
add both equations;
26x=52
x=2
put x=2 in 2
2*2-5y=9
4-9=5y
5y=-5
y=-1
hence, x=2 & y=-1

4x + 3y= 5
2x - 5y= 9?

Using the substitution method
Solve first equation for x:
4x + 3y= 5
4x=5-3y
(1/4) * 4x = (1/4) * (5-3y)
x=5/4 - (3/4)y

Substitute the above value for x in the 2nd equation:
2x - 5y= 9
2*[5/4 - (3/4)y] - 5y = 9
5/2 - (3/2)y - 5y = 9

Rewrite equation with common denominator (2)
5/2 - (3/2)y - (10/2)y = (18/2)

Solve for y:
- (3/2)y - (10/2)y = 18/2 - 5/2
-(13/2)y = 13/2
-(13/2)y * (-2/13) = (13/2) * (-2/13) = -1

So y = -1. Use -1 for y in original equation and solve for x:
4x + 3y= 5
4x + (3)*(-1)= 5
4x - 3 = 5
4x = 8
x = 2

So x=2; y = -1 <---answer

To check your answers;

4x + 3y= 5
4*2 + 3*(-1) = 5
8 - 3 = 5 TRUE

2x - 5y= 9
2*2 - (5)*(-1) = 9
4 - (-5) = 4 + 5 = 9 TRUE

If you solve for x or y in one of the equations, you can just plug in what you get in the other equation.

so, let's solve for x in the first equation.

4x = 5 - 3y
x = 5/4 - 3y/4

Then plug that in for x in the other equation

2 (5/4 - 3y/4) - 5y = 9
10/4 - 6y/4 - 5y = 9
5/2 - 3y/2 - 5y = 9

Multiply both sides by 2 to get rid of the fractions
5 - 3y - 10y = 18
5 - 13y = 18
-13y = 13
y = -1

Then plug that in for y in one of the equations to get x

4x + 3(-1) = 5
4x - 3 = 5
4x = 8
x = 2

so x = 2, y = -1