Answer:
or 
Step-by-step explanation:
Given


Required
Find y

Substitute 


Collect like terms


Split the surd


Rationalize


Take LCM and add


or solve as:


Which question do you need help on
Answer:
Step-by-step explanation:
there is a 125 degree difference between the two
Answer:
If two figures are similar, then the correspondent sides are related by a constant factor.
For example, if the base of one side of one of the figures has a length L, then the correspondent side of the other figure has a length k*L where k is the scale factor.
Let's start with the two left triangles.
In the smaller one the base is 5, and the base of the other triangle is 15.
Then we will have:
15 = k*5
15/5 = k = 3
The scale factor is 3.
Then we will have that:
a = scale factor times the correspondent side in the smaller triangle:
a = k*3 = 3*3 = 9
a = 9
For the other two triangles, the base of the smaller triangle is 12, while the base of the larger triangle is 20.
Then we will have the relation:
12*k = 20
k = (20/12) = 10/6 = 5/3
The scale factor is 5/3
This means that the unknown side b is given by:
b*(5/3) = 15
b = (3/5)*15 = 3*3 = 9
b = 9.
I think the answer is 30....Not sure