Posted by Esther on .
The Everton college store paid 1519 for an order of 41 calculators. The store paid 9 for each scientific calculator. The other, all graphic calculators cost the store 55 each. How many of each type of calculators was ordered?. Thank you

Algebra 1 
Henry,
Esther, check your 2311,1:11am post.

Algebra 1 
Henry,
X Scientific cal.
Y Graphic cal.
Eq1: X + Y = 41.
Eq2: 9X + 55Y = 1519.
Multiply both sides of Eq1 by 9:
9X  9Y = 369,
9X + 55Y = 1519
Add the Eqs:
46Y = 1150,
Y = 1150 / 46 = 25 Graphic cal.
X + 25 = 41,
X = 41 25 = 16 Scientific cal.