2x -3y = 13
4x -y = -9
Multiply the second equation by -3 to make the coefficient of Y opposite the first equation.
4x -y = -9 x -3 = -12x + 3y = 27
Now add this to the first equation:
2x -12x = -10x
-3y +3y = 0
13 +27 = 40
Now you have :
-10x = 40
Divide each side by -10:
x = 40 / -10
x = -4
Now you have a value for x, replace that into the first equation and solve for y:
2(-4) - 3y = 13
-8 - 3y = 13
Add 8 to both sides:
-3y = 21
Divide both sides by -3:
y = 21/-3
y = -7
Now you have X = -4 and y = -7
(-4,-7)
Answer:
30degrees
Step-by-step explanation:
Given
Exterior angle m<CDE = 7x - 19 degrees
interior angles are
m<BCD = 2x - 1
m<DBC = x+10
Since the sum of the interior angles is equal to the exterior, hence;
2x - 1 + x+10 = 7x - 19
3x + 9 = 7x - 19
3x - 7x = -19 - 9
-4x = -28
x = 28/4
x = 7
Get m<CDE
m<CDE = 7x - 19
m<CDE = 7(7) - 19
m<CDE = 49 - 19
m<CDE = 30degrees
