Q. The perimeter of a chalkboard is 18 feet. The area is 18 square feet. What are the dimensions of the board?___ feet by ___ feet
Perimeter Equation: Let's denote the length of the chalkboard as L and the width as W. The perimeter (P) of a rectangle is given by the formula P=2(L+W). We are given that the perimeter is 18 feet, so we have:2(L+W)=18
Isolating Variables: To find the length and width, we need to divide both sides of the perimeter equation by 2 to isolate the L+W term:L+W=218L+W=9
Area Equation: The area A of a rectangle is given by the formula A=L×W. We are given that the area is 18 square feet, so we have:L×W=18
System of Equations: Now we have a system of two equations with two variables:1) L+W=92) L×W=18We can solve this system by substitution or elimination. Let's try substitution. If we solve the first equation for W, we get:W=9−L
Substitution: Substitute W=9−L into the second equation L×W=18:L×(9−L)=18Expanding this, we get:9L−L2=18
Quadratic Equation: Rearrange the equation to form a quadratic equation: L2−9L+18=0
Factoring: We can factor this quadratic equation: (L−3)(L−6)=0
Solving for L: Setting each factor equal to zero gives us the possible values for L:L−3=0 or L−6=0So, L=3 or L=6
Checking Solutions: If L=3, then W=9−L=9−3=6. If L=6, then W=9−L=9−6=3. Both pairs (L=3,W=6) and (L=6,W=3) satisfy the system of equations, so the dimensions of the chalkboard can be 3 feet by 6 feet or 6 feet by 3 feet.
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