Wednesday, July 29, 2015

What is the point of intersection of the lines 16x+14y=-8 and 4x+18y+2=0 ?

We can find the solution to this system of equations by
the elimination method.


Step 1:  Subtract 2 from both sides
of  4x + 18y +2 = 0


The equation becomes 4x + 18y =
-2


Step 2:  Multiply all terms in the equation 4x + 18y =
-2 by -4


The  equation becomes  -16x -72y =
8


Step 3:  Writing both equations in a vertical format,
combine as follows:


16x + 14 y =
-8


-16x  - 72y  = 8


0x  -  72y
= 0


-72y =0


Dividing by -72,  
      y=0


Substitute 0 for y in the first equation  and
solve for x as follows:


16x + 14y =
-8


16x + 14(0) = -8


16x  + 0 =
-8


16x = -8


Dividing by
16,           x = -1/2


Therefore our solution is  {(-1/2,
0)}



We can check our answers by substituting the
values for x and y into both equations.


16x + 14y =
-8


16(-1/2) + 14(0) = -8


-8 =
-8


4x + 18y + 2 =0


4(-1/2) +
18(0) + 2 = 0


-2 +  0 + 2  =
0


0=0


Eliminating is my
favorite part of solving equations!

No comments:

Post a Comment

Calculate tan(x-y), if sin x=1/2 and sin y=1/3. 0

We'll write the formula of the tangent of difference of 2 angles. tan (x-y) = (tan x - tan y)/(1 + tan x*tan y) ...