Answer:
Obi's age is 18 and Oba's age is 9
Step-by-step explanation:
Let Obi's age be x and Oba's age be y
<u><em>Condition 1:</em></u>
x = 2y -----------(1)
<u><em>Condition 2:</em></u>
(x-4) = 3(y-4)
=> x -4 = 3y-12
=> x - 3y = -9 -----(2)
<u><em>Putting eq (1) in (2)</em></u>
2y - 3y = -9
=> -y = -9
=> y = 9
Now,
x = 2y
=> x = 2(9)
=> x= 18
Is there any other information that you can give us?
Answer:
35 is the answer to #8 I believe.
When we need the cosine of the sum of two angles, we use the addition formula for cosine.
When we need the sine of the difference of two angles, we use the difference formula for sine.
Let's try one. Say we needed to know

We're only expected to know the trig functions of 30/60/90 and 45/45/90 triangles. Fortunately,

so


