1. SAT Review 1.Which is the equation of a line that passes through the pt (7, - 1) and is to y + 2x = 1. A. y = 2x – 15 B. y = –2x + 13 C. D. 2.Line p is parallel to line m, x˚- y˚=? A. 0 B. 50 C. 80 D. 100 50˚ x˚ y˚

2. 1.0 -58200-48826-5 2. 0-52200-48826-5 3(0 + 8 + 0 + 4 + 8 + 6) + 5 + 2 + 0 + 8 + 2 + 5 =100, which ends in a zero so it is valid 3(0 + 2 + 0 + 4 + 8 + 6) + 5 + 2 + 0 + 8 + 2 + 5 =82, which ends in a 2 so it is invalid If someone mad a single-digit error, can you tell which digit is incorrect? NO

3. Change one digit in this invalid number s the resulting number is valid. Several answers are possible… 0-52206-48826-5 3. Determine the check digit for the UPC number 38137009213d 3(3 + 1 + 7 + 0 + 2 + 3) + 8 + 3 + 7 + 0 + 9 + 1 + d 69 + d, since the number must end in a zero to be valid…69 + d = 70 So d = 1.

4. 4.Suppose you entered 8 instead of 9 when recording the UPC number 1 55210 02149 6 The difference between 3(9) – 3(8) = 3, so the sum of the weighted sum of the digits in the invalid number cannot end in 0.

5. Determine if the UPC code is valid. 1.1-34987-65432-8 2.2-93847-65674-8 Find the value of the check digit that will make the UPC code valid. 3. 3-02468-13579-d 4. 4-13579-02468-d 5. Come up with 2 valid UPC codes of your own. 6. Check out 2 real UPC codes and see if they are valid under our formula.