Let x be the length and y be the width2x + 2y = 40x + y = 20change that into y = mx + b formy= 20 – x Area =xy = x (20-x) = 20x - x^2Area=-x^2+20xcomplete the square:Area=-(x^2 – 20x + 100) +100=-(x - 10)^2 + 100This is an calculation of a parabola that opens downward with vertex at (10,100), which means maximum area of 100 happens when x, the length=10)Dimensions of the rectangle with maximum area? 10 yds. by 10 yds., a square.
C would be the correct answer. You caanot multiply just one part of an equation, you must multiply the whole thing. All of the other steps follow this rule, so C is an incorrect step, and is therefore the correct choice.
First you would subtract 12 from 60 which is 48. From there you use multiplication to see what numbers would make 48. 8x6 makes 48, so there would be 8 apples in 6 gift baskets! Hopes this helps have a great rest of your day!