Question:
If []x x 11 12 3 45 6 78 9 1 1 = [45] then which one of the following is a value of x?
If []x x 11 12 3 45 6 78 9 1 1 = [45] then which one of the following is a value of x?
Options:
- a) -2
- b) -1
- c) 0
- d) 1
- a) -2
- b) -1
- c) 0
- d) 1
correct answer : d)
Explanation:
x
x
11
12 3
45 6
78 9
1
1[]
= [45]
Þ [x + 11 + 2x + 13 + 3x + 15] 1
1
x
= [45]
Þ x + 11 + 2x + 13 + 3×2 + 15x
= 45
Þ 3×2 + 18x + 24 = 45
Þ x2 + 6x – 7 = 0
Þ x = -7 and 1
x
x
11
12 3
45 6
78 9
1
1[]
= [45]
Þ [x + 11 + 2x + 13 + 3x + 15] 1
1
x
= [45]
Þ x + 11 + 2x + 13 + 3×2 + 15x
= 45
Þ 3×2 + 18x + 24 = 45
Þ x2 + 6x – 7 = 0
Þ x = -7 and 1