# What would be the correct algebraic expression for this question?

Jasmine bought 2 pounds of apples at 3 per pound and 4 pounds of bananas at $1 per pound. Write an algebraic expression for the cost of Jasmine's purchase. What would be the correct algebraic expression for the above question? Would it be a) ( 3 x 2 ) + (1 x 4) OR b) 3a + 1b Would greatly appreciate your help. Thank you in advance. • Pounds here, pounds there. What a confusing question. To begin with, change pounds for kilos...or pounds for dollars, pesos or rubles – DonAntonio Jan 21 '19 at 23:42 • You are correct in both cases. Case$b$is the general case and case$a$is your specific case. – John Douma Jan 21 '19 at 23:57 • @JohnDouma why would b) be the correct general case rather than$2c + 1b$or$2c + 4d$or$3a + 4d$or$ac + 4$or$ac + 4d$or$6 + bd$or... or$ac + bd\$. You have zero unknowns and four knowns. why would you apply any variables? – fleablood Jan 22 '19 at 0:28
• @fleablood I guess the prices could also fluctuate. Still, the answer given is correct. – John Douma Jan 22 '19 at 0:45

Since they're asking for the cost of Jasmine's purchase, I would go with choice (a), since it represents the total cost: $$(3 \times 2) + (1 \times 4)$$.

That being said, if it's a short-answer homework question, then I'd cover my bases and put the general case and explain the substitution of 2 for a and 4 for b.

Hope this helps!

Double check the definition of "algebraic expression" in whatever textbook/workbook you are using. Usually, an algebraic expression is defined as being built from constants, variables (a, b, etc), and algebraic operations (+, -, *, /, ^).

Given the above definition for algebraic expression, I would say:

3a + 1b