We'll use Cramer's rule for 2 equations:
ax + by = e
cx + dy = f
5x -3y = 18 a=5 b=-3 e=18
2x + 7y = -1 c=2 d=7 f=-1
denominator determinant (dn) = (a * d) - (c * b) = 5 * 7 - (2 * -3) = 41
x = [(e * d) - (f * b)] / dn
[18 * 7 - (-1 * -3)] / 41 =
123 / 41 = 3
y = [(a * f) - (c * e)] / dn
= (5 * -1) -(2 * 18) / 41 =
-41 / 41 = -1
Source:
1728.com/cramer.htm
I think this is True. Because Perpendiculer Lines Rely On Right Angles. :)
Answer:
100°= angle b(VERTICAL OPPOSITE ANGLE)
100°+x°=180°[co interior angle]
x=180°-100°
x=80°
(9x^2 +4x -7) - x^2 +2x - 6
8x^2 +6x - 13.
Get a grip on your life son. This is really simple.
For future reference, it would be easier to say 8 and a half miles. Just a tip for better understanding. Now I am pretty sure the answer would be the first one. You would take the total divided by the variable of each day to get the number of days
