2x + y = 5
2y + x = 4
This is SIMULTANEOUS Equations.
To solve , arbitrarily select a letter to eliminate, In this case 'x'
To do this the coefficients of 'x' must be the same , but of opposite sign. Hence multiply the bottom equation by '-2'
Hence
2x + y = 5
-2x - 4y = =8
Add
-3y = -3
Divide both sides by '-1'
3y = 3
y = 1
When y= 1
Substitute back in to either eq'n
2x + 1 = 5
Subtract '1' from both sides
2x = 4
x = 2
Hence the answer is ( x,y) = ( 2,1)
parallel
-2x + 2y = 4 is equivalent to twice -2 + y = 2 which is the equation of a straight line.
2y = 4x + 4y = 2x + 2
k
(-2, 4)
(4, -1)
If: 12 = 2y+x then y = -1/2x+6 So: y = 2x+4 and y = -1/2x+6 which means that they are perpendicular lines
x = 2y = 4
4x + 2y = -8 → 2y = -4x - 8 → y = -2x - 4
-2X + 2Y = 4 2Y = 2X + 4 Y = X +2 by inspection, 2 but, you could also 0 out X in original equation -2(0) + 2Y = 4 2Y = 4 Y = 2
They are straight lines.
1 solution