Answer:
9 x + 8 y = 10 (I)
y = -4x + 7 (II)
One way is to rewrite the second as
4x + y = 7
Now multiply this equation by 8
32 x + 8 y = 56
9 x + 8 y = 10 and now subtract the equations
23 x = 46 this gives x as 2
From equation (II) y = -4 (2) + 7 = -1
So our values are (2, -1)
Check:
(I) 9 x + 8 y = 10 9 * 2 - 8 = 10
(II) 4 x + y = 7 or 4 * 2 - 1 = 7
Or you can substitute equation (II) directly into equation (I)
( 'x' is not 144 .)
The supplement of an angle is (180 - x) .
The problem says that (2/3) of 'x' is equal to (180 - x) .
180 - x = 2/3 x
Multiply each side by 3 :
( Note: 3 x 180 = 540 .)
540 - 3x = 2x
Add 3x to each side:
540 = 5x
Divide each side by 5 :
<u>x = 108°</u> .
The location to the nonegative abscissa, positive ordinate is in the Q1 it means it is in the fisrt quadrant as seen in the next image: http://www.mathnstuff.com/math/spoken/here/1words/q/q2.htm
Hope this helps
