Question

Please help me with this problem

Answer 1

Answer:

Keisha bought 3 sandwiches and 5 lemonades.

Equations:  x + y = 8       2x + y = 11

Step-by-step explanation:

To solve a problem with two variables, you need to set up a system of equations comparing the two variables and solve using either substitution or elimination.  If 'x' represents the number of sandwiches and 'y' represents the number of lemonades, then x + y = 8 because they bought a total of 8 items.  Also, the cost of each item is given as well as the total amount of money spent.  So, our second equation is: 2x + y = 11.   We can use inverse operations to solve for 'y' in the first equation:  x + y - x = 8 - x which simplifies to: y = 8 - x.  We can then use this expression to substitute in for the variable 'y' in the second equation:  2x + 8 - x = 11.

Combine like terms:  x + 8 = 11

Inverse Operations: x +8 - 8 = 11 - 8

Solve:  x = 3, so Keisha bought 3 sandwiches

Solve for y:  y = 8 - 3 = 5, so Keisha bought 5 lemonades