evaluate the following expression x y xy if x 4 and y 2

HESI A2

HESI A2 Math Practice Exam

1. Evaluate the following expression: -x + y + xy, when x = 4 and y = 2.

A. 2
B. 6
C. 12
D. 8

Correct answer: B

Rationale: To evaluate the expression, substitute x = 4 and y = 2 into the expression: -4 + 2 + 4*2. Calculate each term: -4 + 2 = -2, then 4*2 = 8. Adding these results gives -2 + 8 = 6. Therefore, the correct answer is 6. Choice A (2) is incorrect as it does not consider all terms in the expression. Choice C (12) is incorrect as it miscalculates the result by failing to account for the negative sign. Choice D (8) is incorrect as it doesn't consider the negative value of the first term in the expression.

2. Ratio and proportion 1.2:x=14:42.

A. 2
B. 0
C. 1
D. 3

Correct answer: D

Rationale: Cross-multiply to solve for 𝑥 x: 1.2 × 42 = 14 𝑥 1.2×42=14x 50.4 = 14 𝑥 50.4=14x 𝑥 = 50.4 14 = 3.6 x= 14 50.4 =3.6

3. In his stamp collection, Bruno has 15 more stamps from Europe than from Africa, and 18 more stamps from Asia than from Africa. If he has 27 stamps from Europe, how many Asian stamps does he have?

A. 12
B. 22
C. 30
D. 40

Correct answer: C

Rationale: Since Bruno has 27 stamps from Europe, which is 15 more than from Africa, he must have 27 - 15 = 12 stamps from Africa. Since he also has 18 more stamps from Asia than from Africa, he must have 12 + 18 = 30 stamps from Asia. Therefore, Bruno has 30 Asian stamps. Choice A (12) is the number of stamps Bruno has from Africa, not Asia. Choices B (22) and D (40) are not derived from the correct calculations based on the given information.

4. What is the result of multiplying 10 by 5?

A. 65
B. 50
C. 45
D. 55

Correct answer: B

Rationale: The correct answer is B. To find the result of multiplying 10 by 5, you perform the calculation: 10 × 5 = 50. Choices A, C, and D are incorrect because they do not represent the accurate product of 10 multiplied by 5.

5. How many grams are in 6 kilograms?

A. 600 grams
B. 6000 grams
C. 600 grams
D. 60,000 grams

Correct answer: B

Rationale: There are 1,000 grams in a kilogram. Therefore, to convert kilograms to grams, you need to multiply the number of kilograms by 1,000. In this case, 6 kilograms would be equal to 6 × 1,000 = 6,000 grams. Choices A, C, and D are incorrect because they do not apply the correct conversion factor from kilograms to grams.