Question

the length of a rectangle is 3 meters more than its width. if the area is 40 m², what is the width? 8 m 5 m 10 m 7 m

Explanation:

Step1: Let the width be $x$ meters.

The length is $x + 3$ meters.

Step2: Use the area formula for rectangle.

The area of a rectangle $A=length\times width$, so $40=(x + 3)\times x$, which simplifies to $x^{2}+3x - 40=0$.

Step3: Factor the quadratic equation.

We factor $x^{2}+3x - 40$ as $(x + 8)(x - 5)=0$.

Step4: Solve for $x$.

Setting each factor equal to zero gives $x+8 = 0$ or $x - 5=0$. So $x=-8$ or $x = 5$. Since the width cannot be negative, we discard $x=-8$.

Answer:

B. 5 m