Question

Solve 7x + 5y = 14 using matrices.
4x + 3y = 9

A (7, -3)

B (-3, 7)

C (3, -7)

D (7, 3)

Answer 1

typing out martices r a pain let me see if i can do it clearly

Answer 2

7 5 | 14
4 3 | 9
this is how we wld set up out matrix now that line that u see is just to show that 14 and 9 are the right side of the equation

Answer 3

so inorder to row reduce we must multiply the first row by 4 and the second row by 7
28 20 | 56
28 21 | 63

ok this may be a lil complicating but this is the way i learned it so now u gotta subtract the rows
28 20 | 56
0 -1 | -7

Answer 4

did u follow so far?

Answer 5

we can even reduce more if u wld like

Answer 6

lets remove the negatives and we will also replace the 28 with a 1

Answer 7

Ok so lets divide the top row by 28
1 (5/7) | 2
0 -1 | -7
now lets remove the negative by dividing the second row by -1
1 (5/7) | 2
0 1 | 7