Problema Solution
If the sides of a square are lengthened by 7in., the area become 121in.. Find the length of a side of the original square
Answer provided by our tutors
1) 5x^2(7x - 5) + 2(7x - 5) = (7x - 5)(5x^2 + 2)
2) 4a^2(2a + 7) - 2(2a + 7) = 2(2a + 7)(2a^2 + 1)
Factor:
1) x(7x - 3) = 0
x = 0 or 7x - 3 = 0
................7x = 3
.................x = 3/7
2) 3x^2 - 5x + 2 = 0
(x - 1)(3x - 2) = 0
x - 1 = 0 or 3x - 2 = 0
x = 1...........3x = 2
....................x = 2/3
Word problem
1) Let s = length of side of original square
(s + 7)^2 = 121
s + 7 = ± 11
s = -7 ± 11
s = 4 or -18 (reject)
The length of the side of the original square was 4 in.