Answer :
Answer:
Marie bought 15 large sweatshirts
Explanation:
In this case we have 2 equations with two unknowns, x and y, which represent the number of sweatshirts of $ 9 and $ 7 respectively.
[tex]x+y=37 (1)\\289=9x+7y (2)[/tex]
Rewriting equation 1 for x:
[tex]x=37-y[/tex]
Using the substitution method, substituting x = 37-y into
equation 2:
[tex]289=9(37-y)+7y[/tex]
Simplify and solve the equation for y:
[tex]289 = 333-9y + 7y\\9y-7y = 333-289\\2y = 44\\y = 44/2 = 22[/tex]
Substituting y=22 into
equation 1:
[tex]x + 22 = 37[/tex]
Simplify and solve the equation for x:
[tex]x = 37-22 = 15[/tex]
Therefore Marie bought 15 large sweatshirts and 22 small sweatshirts with his $289