Answer: 4. A
5. C
6. B
Step-by-step explanation:
2 is the answer 23:35677544
Answer:
Solution : (15, - 11)
Step-by-step explanation:
We want to solve this problem using a matrix, so it would be wise to apply Gaussian elimination. Doing so we can start by writing out the matrix of the coefficients, and the solutions ( - 5 and - 2 ) --- ( 1 )

Now let's begin by canceling the leading coefficient in each row, reaching row echelon form, as we desire --- ( 2 )
Row Echelon Form :

Step # 1 : Swap the first and second matrix rows,

Step # 2 : Cancel leading coefficient in row 2 through
,

Now we can continue canceling the leading coefficient in each row, and finally reach the following matrix.

As you can see our solution is x = 15, y = - 11 or (15, - 11).
Step-by-step explanation:
so ,
Question 6 :-
5 × (3+4) - 4
first solve the Bracket ......
5 × (7) - 4
after multiplication ......
35 - 4
= 31
so , Answer is 1st one ....
Question 7 :-
8 + 1/2 × (6-2) -1
so , here also solve the Bracket first .....
8 + 1/2 × (4) - 1
after multiplication .....
8 + 2 - 1
after + and - .......
10 - 1
= 9 .......
so , Answer is 2nd one .....