math help??

Question

0.5x+0.4y= -1
0.3x+0.6y= -0.6
help please

Answer 1

Isolate "x" or "y" in either equation. Let's isolate "y" in the 1st equation.

First: subtract 0.5x from both sides (when you move a term to the opposite side, always use the opposite sign).

0.5x-0.5x+0.4y= -1-0.5x
0.4y= -1-0.5x (divide each term by 0.4)
(0.4y)/0.4 = (-1)/0.4 - (0.5x)/0.4)
y = -2.5 - 1.25x

Sec: substitute -2.5-1.25x with "Y" in the 2nd equation.

0.3x+0.6(-2.5-1.25x) = -0.6
0.3x+0.6(-2.5)+0.6(-1.25x) = -0.6
0.3x-1.5-0.75x = -0.6
-0.45x -1.5 = -0.6 (add 1.5 with both sides).
-0.45x -1.5+1.5 = -0.6+1.5
-0.45x = 0.9 (divide both sides by -0.45)
(-0.45x)/-0.45 = (0.9)/-0.45
x = -2

Third: substitute -2 with "x" in the 1st equation.

(0.5)(-2)+0.4y= -1
-1+0.4y= -1 (add 1 with both sides).
-1+1+0.4y= -1+1
0.4y = 0 (divide both sides by 0.4)
(0.4y)/0.4 = 0/(0.4)
y = 0

Solution Set: (-2,0)

Answer 2

0.5x + 0.4y = -1
0.3x + 0.6y = -0.6
15x + 12y = - 30
15x + 30y = - 30
y = 0
x = - 2

Answer 3

Multiply first equation by 3
1.5x+1.2y=-3 .............(3)
Multiply second equation by 2
0.6x + 1.2y = -1.2 .............(4)
subtract (4) from (3)
0.9x=-1.8
x=-2
Put value of x in first equation
-1+0.4y=-1
y=0
Ans. x=-2, y=0

Answer 4

Having math problems of my own gotta do 15 pages by tomorow sooo y am i still online?

Answer 5

multiply eq 1 by 3 and eq 2 by 2
we get
1.5x+1.2y=-3..............eq 3
0.6x+1.2y=-1.2............eq4
now substract eq 4 frm 3
we get
0.9x+0=-1.8
i.e
x=-0.2
put this in eq i
we get
-1+0.4y=-1
therefore
y=0
hence soln(x,y)=(-0.2,0)