Convert the system to an augmented matrix.

Question

Convert the system to an augmented matrix.



2x +  y = 7

4x − 5y = 2

Answer 1

2 1 | 7

4 -5 | 2

row2 = -2 * row1 + row2

2 1 | 7

0 -7 | -12

-7y = -12

y = -12/-7 = 12/7

2x + y = 7

2x + 12/7 = 7

14x + 12 = 49 <--- multiplies by 7

14x = 37

x = 37/14

check: 2(37/14) + 12/7 = 68/7 + 12/7 = 37/7 + 12/7 = 49/7 = 7

check: 4(37/14) - 5(12/7) = 74/7 - 60/7 = 14/7 = 2