
Thomas H. answered 02/08/23
Different Approaches! Fill in the Gaps!
The length of a rectangle is 5 inches less than twice its width. It’s area is 88 inches squared. Find the length and width of the rectangle
LENGTH - 5 = 2(WIDTH)
LENGTH • WIDTH = 88
LENGTH - 5 = 2(WIDTH)
LENGTH = 2(WIDTH) + 5
[2(WIDTH) + 5] • WIDTH = 88
W(2W+5)=88
2W2 +5W = 88
2W2 +5W - 88 = 0
FACTOR:
a = 2, b = 5, c = -88
c<0 (different signs)
b>0 (larger number is positive)
(w + ?)(w - ?)
ac= -176
what pairs of factors of -176 add up to 5? (try them all out)
factors: 1,176; 2,88; 4,44; 8,22; 11,16
(w + 16)(w - 11)= 0
w + 16 = 0 or w - 11 = 0
w= -16, 11
answer must be positive: w = 11
another way to find factors is to graph 2W2 +5W - 88 = 0
where they cross the x-axis, are the 2 answers.
Thomas Hirschman