Answer:
B
Step-by-step explanation:
The second equation in system B is only in terms of y, so we need to use elimination to eliminate the x term from the second equation in system A.
To do that, we need to multiply the first equation by 5.
5 (-x − 2y = 7)
-5x − 10y = 35
Add to the second equation. Notice the x terms cancel out.
(-5x − 10y) + (5x − 6y) = 35 + (-3)
-16y = 32
Combining this new equation with the first equation from system A will get us system B.
-x − 2y = 7
-16y = 32
Answer:
x = 71°
Step-by-step explanation:
By applying triangle sum theorem in ΔBHD,
m∠DBH + m∠BHD + m∠HDB = 180°
40° + m∠BHD + 31° = 180°
m∠BHD = 180° - 71° = 109°
m∠BHD + m∠DHE = 180° [Linear pair of angles]
109° + x° = 180°
x = 180° - 109°
x = 71°
Answer: I think it is B
Step-by-step explanation: