Answer:
39
Step-by-step explanation:
284-5(7)²
284-(5×49)
284-245
39
Answer:
X= -12 Y=10
Step-by-step explanation:
Answer:

Step-by-step explanation:
Let x, y , and z be the numbers.
Then the geometric sequence is 
Recall that term of a geometric sequence are generally in the form:

This implies that:
a=32 and 
Substitute a=32 and solve for r.


Take the fourth root to get:
![r=\sqrt[4]{\frac{81}{256} }](https://tex.z-dn.net/?f=r%3D%5Csqrt%5B4%5D%7B%5Cfrac%7B81%7D%7B256%7D%20%7D)

Therefore 


Answer:
Cos 74°= Sin 16°
Sin 20°= Cos 70°
Sin A°=Cos (90°- A°)
Step-by-step explanation:
This is because the three pairs are complementary i.e they add up to 90° and in trigonometric ratios, complementary ratios are equal.
Let x be the length of the train.
On the basis of the observer;
Speed of the train = x/6
On the basis of the bridge;
Total distance covered by any point of the train= 350+x
Speed = (350+x)/20
Equating the two expressions of speed;
x/6 = (350+x)/20
20(x) = 6(350+x)
20x = 2100+6x
(20-6)x = 2100
14x = 2100
x= 2100/14 = 150 m
Speed = x/6 = (350+x)/20 = 150/6 = 500/20 = 25 m/s.
Therefore,
Length of train = 150 m
Speed of train = 25 m/s