Since the first equation already gives you y, substitute Y for 4x in the second equation.
y=4x
x+y=5
x+(4x)=5
5x=5
x=1
Now that you know x, plug in x for 1 in the first equation.
y=4(1)
y=4
Answer: (1,4)
A ratio of 2:3 is the same as 2/3 now we can divide out 2/3 to .6666666 and then multiply by 10 to get 6.666666 or you could just multiply 10 x 2/3 to get 20/3 and then divide to get 6.66666.
11.3057558 is the answer when you multiply/add/subtract it all.
Answer:
18°
Step-by-step explanation:
The law of cosines tells you ...
a² = b² + c² -2bc·cos(A)
Solve for cos(A) and fill in the numbers. Note that the value of cos(A) is very close to 1, so the angle will be fairly small. This by itself can steer you to the correct answer.
cos(A) = (b² +c² -a²)/(2bc) = (49 +100 -16)/(2·7·10) = 133/140
A = arccos(133/140) ≈ 18.2° ≈ 18°
