The solution is (8,-12) if it was solved by elimination
You are given a rectangle and are told that the length is 1 cm more than twice the width of the rectangle. The area of the rect. is also given, and is 21 cm^2.
Find the length and width. To do this, represent the length by y and the width by x. Then "1 cm more than twice the width" comes out to y=2x+1 (cm).
Since the area of a rect. is equal to the product of its length and width,
x(2x+1)=21 cm^2. Multiply out x(2x+1). show your work. Next, subtract 21 from both sides. Write your algebraic expression on the left side as a quadratic equation in standard form.
Solve this quadratic equation for x. Recall that x (in cm) will represent the width of the rect., and y=2x+1 (in cm) will repr. the length.
X=5 this is the root to the equation
Rectangle formula 1/2 ×b × H × l
= 1
___ × 4 × 86 × 2 = 344 totally answer
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