Answer:
w = 70 cm
A = 5600cm^2
Step-by-step explanation:
P = 2(l+w) where l is the length and w is the width
300 = 2(l+w)
We know the length is 10 longer than the width
l = w+10
300 = 2(w+10+w)
Divide each side by 2
300/2 = (w+10+w)
150 = (2w+10)
Subtract 10 from each side
150-10 = 2w
140 = 2w
Divide by 2
140/2 = w
70 = w
Now find the area
A = l*w
A = (w+10) * w
= (70+10) *70
= 80*70
5600
