The sum of the opposite interior angles is equal to the exterior angle.
So,
∠CAB + ∠ACB = ∠CBD
x + 40 + 3x + 10 = 6x
4x + 50 = 6x
2x = 50
x = 25°
∠CAB = x + 40 = 25 + 40 = 65°
Hence, the answer is D.
Answer:
3rd
Step-by-step explanation:
Answer:
35
Step-by-step explanation:
Alright this is like a linear pair. All three angles add up to 180; so this is the set up:
40 + 2x + 30 + 40 = 180
2x + 110 = 180
2x = 70
x=35
With amounts measured in gallons, let
x = amount of 65% antifreeze
y = amount of 90% antifreeze
1 gal of the 65% brand contains 0.65 gal of pure antifreeze; x gal would contain 0.65x gal. Similarly, y gal of the 90% brand contains 0.90y gal of pure antifreeze.
To obtain 120 gal of 80% antifreeze solution (which contains 0.80•120 = 96 gal of pure antifreeze), we must have
x + y = 120 … … … … … [total volume of antifreeze solution]
0.65x + 0.90y = 96 … [total volume of pure antifreeze]
Solve the first equation for y :
y = 120 - x
Substitute this into the second equation and solve for x :
0.65x + 0.90 (120 - x) = 96
0.65x + 108 - 0.90x = 96
0.25x = 12
x = 48
Solve for y :
y = 120 - 48
y = 72
