- #1

lyd123

- 13

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Hi,how do I go about answering the attached question? I know that for a matrix to have no solution, there needs to be a contradiction in some row. Unique solutions is when m* ${x}_{3}$ =c , where m* ${x}_{3}$ $\ne$ 0.

One way I tried was if a=0,

then from row (1) : b* ${x}_{3}$ =2

${x}_{3}$= 2/b (from row 2 : 2/b = 1 , so b=2)

then from row (2) : 4* ${x}_{3}$ =4

${x}_{3}$= 1

then from row (3) : 2* ${x}_{3}$ =b

${x}_{3}$= b/2 (from row 2 : b/2 = 1 , so b=2)

This seems to work, so when a=0, and b =1 , you have unique solutions?

How do I answer this question? Thanks.View attachment 8733

One way I tried was if a=0,

then from row (1) : b* ${x}_{3}$ =2

${x}_{3}$= 2/b (from row 2 : 2/b = 1 , so b=2)

then from row (2) : 4* ${x}_{3}$ =4

${x}_{3}$= 1

then from row (3) : 2* ${x}_{3}$ =b

${x}_{3}$= b/2 (from row 2 : b/2 = 1 , so b=2)

This seems to work, so when a=0, and b =1 , you have unique solutions?

How do I answer this question? Thanks.View attachment 8733