The Alternate Interior Angle theorem states that when the lines are parallel, the alternate interior angles are equal. Since lines AB and CD are parallel, m∠ACD and m∠BAC are equal. So, the equation would be

or

.
2x - y = 5
x + 3y = 7
I'm assuming you mean the coefficient matrix.
Given:
Total number of calculators in a box = 10
Defective calculators in the box = 1
To find:
The number of ways in which four calculators be selected and one of the four calculator is defective.
Solution:
We have,
Total calculators = 10
Defective calculators = 1
Then, Non-defective calculator = 10-1 = 9
Out of 4 selected calculators 1 should be defective. So, 3 calculators are selected from 9 non-defective calculators and 1 is selected from the defective calculator.






Therefore, the four calculators can be selected in 84 ways.
Step-by-step explanation:
6 - 4a < 2
6 - 2 < 4a
4 < 4a
1 < a
6 - a > 2
6 - 2 > a
4 > a
3a - 1 < 8
3a < 8 + 1
3a < 9
a < 3