AlgebraHardPerimeter equation for a rectangle
Algebra practice question
A rectangle's length is 6 centimetres more than its width w. Its perimeter is 60 centimetres. Which equation can be used to find w?
- A. 2w + 2(w + 6) = 60Correct
- B. w + (w + 6) = 60
- C. w(w + 6) = 60
- D. 2w + 6 = 60
Answer: A. 2w + 2(w + 6) = 60
Perimeter = 2(width) + 2(length) = 2w + 2(w + 6). Setting it equal to 60 gives w = 12.
Why the other answers are wrong
- B. w + (w + 6) = 60
- w + (w + 6) is only half the perimeter.
- C. w(w + 6) = 60
- w(w + 6) is the AREA.
- D. 2w + 6 = 60
- 2w + 6 forgets to double the length.
More Algebra questions
- Hard
For how many integer values of x is −2 < (x − 5)/3 ≤ 1 true? - Hard
The system 2x + 3y = 6 and 4x + 6y = k has infinitely many solutions. What is the value of k? - Hard
Which of the following is the complete solution set to |x − 4| < 6? - Hard
A student has $40 to spend on notebooks costing $4 each and pens costing $2 each, and wants at least 12 items … - Hard
What is the least whole number of minutes of international calling in a month for which the total monthly cost… - Hard
How many liters of the 30% acid solution did the technician use?
Not affiliated with the College Board. SAT is a trademark of the College Board.