Answer:
length: 13 cm
width: 5 cm
Step-by-step explanation:
You may be aware that 65 = 5×13. We note that 13 is 3 more than twice 5, so these are the dimensions of the rectangle:
5 cm wide; 13 cm long
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If you want so solve this algebraically, you can let w represent the width. Then the length is 2w+3 and the area is ...
A = LW
65 = (2w+3)(w)
In standard form, this equation is ...
2w^2 +3w -65 = 0
To factor this, you look for factors of 2×(-65) = -130 that have a sum of 3. Those would be ...
-130 = (-10)(13)
Then the factored equation is ...
2w^2 +13w -10w -65 = 0
w(2w+13) -5(2w+13) = 0
(w -5)(2w +13) = 0 ⇒ w = 5, -13/2
The positive solution makes sense in this problem, so ...
width = 5 cm
length = 2(5) +3 = 13 cm
