A person buys q1, q2, q3 and q4 units of four goods whose prices per unit are, re- spectively, $1, $2, $3 and $4. What is the total expenditure? What will be the total expenditure if the prices change to $4, $3, $2 and $1 per unit respectively?

Step-by-step explanation:

Quantity of good1 = q1

Unit price of good1 = $1

Quantity of good2 = q2

Unit price of good2 = $2

Quantity of good3 = q3

Unit price of good3 = $3

Quantity of good4 = q4

Unit price of good4 = $4

Total expenditure =

=

If the prices change to $4, $3, $2 and $1 per unit respectively, total expenditure =

15

step-by-step explanation:

we are given the following expression and we are to solve it and find the product:

-13 × (-5)

solving the given expression in the standard order of solving a mathematical expression, beginning with the opening of brackets and then multiplying the terms and changing their signs.

-3 × -5 = 15 (answer is positive because when negative is multiplied with negative, it gives a positive answer)