Answer:
y = 5x - 5/2xy + 79
Explanation:
First we need to solve for m which is slope.
Subtract 5y from both sides
2x = 10 - 5y
Then divide each term by 2
2x/2 = 10/2 + -5y/2
Then simplify to the left
x = 10/2 + -5y/2
Then simplify the right side
x = 5 - 5y/2
Next we have to find the value of b using the formula y = mx + b
So
y = (5 - 5y/2) * x + b
y = (5 - 5y/2) * (4) + b
9 = (5 - 5(9)/2) * (4) + b
Rewrite
(5 - 5(9)/2) * 4 + b = 9
Simplify more
Multiply 5 by 9
(5 - 45/2) * 4 + b = 9
Multiply by 2/2 to write 5 as a fraction
5 * 2/2 - 45/2) * 4 + b = 9
Then combine 5 and 2/2
(5 * 2/2 - 45/2) * 4 + b = 9
Combine the numerator over the denom
5 * 2 - 45/2 * 4 + b = 9
Simplify the numerator
-35/2 * 4 + b = 9
Cancel the common factor of 2
-35 * 2 + b = 9
Multiply
-70 + b = 9
Move the terms without b to the right side
b = 9 + 70 > b = 79
Now we substitute all the values into y = mx + b
y = 5x - 5/2xy + 79