math
posted by krystal .
write an equation of the line that passes through the given points:
1.(1,0),(0,2)

m = y2  y1 / x2  x1
m = 2  0 / 0  (1)
m = 2/1
m = 2
point slope form
y  y1 = m (x  x1)
y  0 = 2 (x  (1))
y = 2 (x + 1)
y = 2x  2 
the slope of the line is:
(2  0) /( 0 + 1) = 2
the slope of the line is also
(y0)/(x+1) = slope from any point on the line to (1,0)
so
y /(x+1) = 2
y = 2 x  2

now check
0 = 2 (1)  2 yes
2 = 2(0) 2 yes so we got it.