y = mx + b slope(m) = -1 use either of ur points.... (1,3)...x = 1 and y = 3 now sub into the formula and find b, the y int 3 = -1(1) + b 3 = -1 + b 3 + 1 = b 4 = b so the equation for this line is : y = -1x + 4 which is usually written as : y = -x + 4
Now...to find where the line crosses the x axis (or the x intercept)...we sub in 0 for y and solve for x
y = -x + 4 0 = -x + 4 x = 4... so ur x intercept (where the line crosses the x axis) is : (4,0)