Question

Sarah and Brian went shopping and spent a total of 47.50 brian spent 15.50 less than sarah how much did brian spend

Answer 1

you could do it this way
let brian spend x and Sarah spend y dollars

so we have the equation

x + y = 47.50

Answer 2

and since Brian spent 15.50 less than Sarah

y - x = 15.50

Answer 3

now solve this system;-

x + y = 47.50
y - x = 15.50

Answer 4

Hint: add the 2 equations to get an equation in y only
solve this to get what Sarah spent.
Then find brians amount by subtracting 15.50 from Sarah's.

Answer 5

answer is 16