a = 1, b =14 and y-coordinate is 6 when x = 0.
Solution:
Let us first write the equation of a line.
Take the points are (2, 2) and (6, 10).
Slope of the line:
m = 2
Point-slope formula:
y - 10 = 2(x - 2)
y - 10 = 2x - 4
Add 10 on both sides,we get
y = 2x + 6
Equation of a line is y = 2x + 6.
To find (a, 8), substitute x = a and y = 8 in the equation,
8 = 2a + 6
Subtract 6 from both sides, we get
2 = 2a
a = 1
To find (4, b), substitute x = 4 and y = b in the equation,
b = 2(4) + 6
b = 8 + 6
b = 14
Substitute x = o in the equation.
y = 2(0) + 6
y = 6
The y-coordinate is 6 when x = 0.