This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
We know that the line has intercepts (x,0) and (0,y). And the sum of x and y is 5. So we have the first equation: x + y = 5

Using the formula for the slope of a line we have:
m =  \frac{0-y}{x-0}  \frac{-y}{x} = 3
Thus, y = -3x

We now have a system of equation. Using substitution,
x -3x = 5
-2x = 5
x =  \frac{-5}{2}
Therefore, y =  \frac{15}{2}

Substitute to y = mx +b, the equation of the line is
y = 3x + 15/2