The Total solution for NCERT class 6-12
Solve the following system of equations by matrix method:
(i) 5x + 7y + 2 = 0
4x + 6y + 3 = 0
(ii) 5x + 2y = 3
3x + 2y = 5
(iii) 3x + 4y – 5 = 0
x – y + 3 = 0
(iv) 3x + y = 19
3x – y = 23
(v) 3x + 7y = 4
x + 2y = -1
(vi) 3x + y = 7
5x + 3y = 12
Answer - 1 : -
(i) Given 5x + 7y + 2= 0 and 4x + 6y + 3 = 0
Hence, x = 9/2and y = -7/2
(ii) Given 5x + 2y = 3
Hence, x = -1and y = 4
(iii) Given 3x + 4y –5 = 0
Hence, X = 1 Y = – 2
(iv) Given 3x + y = 19
(v) Given 3x + 7y = 4
(vi) Given 3x + y = 7
(i) x + y –z = 32x + 3y + z = 103x – y – 7z = 1
(ii) x + y + z = 3
2x – y + z = -1
2x + y – 3z = -9
(iii) 6x – 12y + 25z = 4
4x + 15y – 20z = 3
2x + 18y + 15z = 10
(iv) 3x + 4y + 7z = 14
2x – y + 3z = 4
x + 2y – 3z = 0
(v) (2/x) – (3/y) + (3/z) = 10
(1/x) + (1/y) + (1/z) = 10
(3/x) – (1/y) + (2/z) = 13
(vi) 5x + 3y + z = 16
2x + y + 3z = 19
x + 2y + 4z = 25
(vii) 3x + 4y + 2z = 8
2y – 3z = 3
x – 2y + 6z = -2
(viii) 2x + y + z = 2
x + 3y – z = 5
3x + y – 2z = 6
(ix) 2x + 6y = 2
3x – z = -8
2x – y + z = -3
(x) 2y – z = 1
x – y + z = 2
2x – y = 0
(xi) 8x + 4y + 3z = 18
2x + y + z = 5
x + 2y + z = 5
(xii) x + y + z = 6
x + 2z = 7
3x + y + z = 12
(xiii) (2/x) + (3/y) + (10/z) = 4,
(4/x) – (6/y) + (5/z) = 1,
(6/x) + (9/y) – (20/z) = 2, x, y, z ≠ 0
(xiv) x – y + 2z = 7
3x + 4y – 5z = -5
2x – y + 3z = 12
Answer - 2 : - (i)
Show that each one of the following systems of linear equations isconsistent and also find their solutions:
(i) 6x + 4y = 2
9x + 6y = 3
(ii) 2x + 3y = 5
6x + 9y = 15
(iii) 5x + 3y + 7z = 4
3x + 26y + 2z = 9
7x + 2y + 10z = 5
(v) x + y + z = 6
x + 2y + 3z = 14
x + 4y + 7z = 30
(vi) 2x + 2y – 2z = 1
4x + 4y – z = 2
6x + 6y + 2z = 3
Answer - 3 : - (i)
Show that each one of the following systems of linear equations isconsistent:
(i) 2x + 5y = 7
6x + 15y = 13
6x + 9y = 10
(iii) 4x – 2y = 3
6x – 3y = 5
(iv) 4x – 5y – 2z = 2
5x – 4y + 2z = -2
2x + 2y + 8z = -1
(v) 3x – y – 2z = 2
2y – z = -1
3x – 5y = 3
(vi) x + y – 2z = 5
x – 2y + z = -2
-2x + y + z = 4
Answer - 4 : - (i)
Answer - 5 : -
Answer - 6 : -
Answer - 7 : -
Using A-1,solve the system of linear equations X - 2y = 10, 2x + y + 3z = 8 and -2y + z = 7
5.
Answer - 8 : - 1.
Answer - 9 : -
An amount of ₹10,000 is put into three investments at the rate of 10, 12and 15% per annum. The combined incomes are ₹1310 and the combined income offirst and second investment is ₹ 190 short of the income from the third. Findthe investment in each using matrix method.
Answer - 10 : -