In order to find the equation of a line, you would have to use the equation y=mx+b.
First, find the slope:

There is (1,8) and (2, 16) so plug that in 16-8/2-1 = 8. That's your slope! (Or the m)
Next in order to find b, you have to plug in a point:
y=8x+b
Take (1,8) and plug it in for x and y:
8=8(1)+b
b=0
Your y intercept is 0 (which you can also see on the graph)
So your answer is: y=8x
The answer is variant A.
Because:
if the two angles of a triangle are congruent to two angles of the other triangle , this triangles are similar
Rules of exponents and the distributive property apply.
(x+y)² = (x+y)·(x+y) . . . . . meaning of exponent of 2
= x·(x+y) +y·(x+y) . . . . . . . distributive property
= x·x +x·y +y·x +y·y . . . . . distributive property
= x² +x·y +x·y +y² . . . . . . meaning of exponent of 2, commutative property of multiplication
= x² +(1+1)·x·y +y² . . . . . . distributive property
= x²+2xy+y² . . . . . . . . . the desired form
Thus
(x+y)² = x²+2xy+y²