13 because 1/4 times 4 is 4/4 with makes is a 1
And 3 times 4 is 12
1+12=13.
If the y intercept isn't -5 go to ur coordinate that is given and find where the y intercept is and plug in the y intercept to y=mx+b
Split it up into 3 separate shapes.
Rectangle 1 = 15 x 3 = 45
Rectangle 2 = 3 x 5 = 15
Triangle = 1/2 x 5 x 3 = 7.5
Total area = 45 + 15 + 7.5 = 67.5 cm²