Answer: y = 9x - 11
Step-by-step explanation:
The equation of a straight line can be represented in the slope-intercept form, y = mx + c
Where c = y intercept
m represents the slope of the line.
m = (y2 - y1)/(x2 - x1)
y2 = final value of y
y 1 = initial value of y
x2 = final value of x
x1 = initial value of x
The line passes through (4, 25) and (8, 61),
y2 = 61
y1 = 25
x2 = 8
x1 = 4
Slope,m = (61 - 25)/(8 - 4) = 36/4 = 9
To determine the y intercept, we would substitute x = 4, y = 25 and m= 9 into y = mx + c. It becomes
25 = 9 × 4 + c
25 = 36 + c
c = 25 - 36
c = - 11
The equation becomes
y = 9x - 11
