SOLUTION: It takes Akira 10 minutes to make a black and white drawing and 25 minutes for a color drawing. On Saturday he made a total of 9 drawings in 2 hours. Write and solve a system of eq

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: It takes Akira 10 minutes to make a black and white drawing and 25 minutes for a color drawing. On Saturday he made a total of 9 drawings in 2 hours. Write and solve a system of eq      Log On


   

Question 837598: It takes Akira 10 minutes to make a black and white drawing and 25 minutes for a color drawing. On Saturday he made a total of 9 drawings in 2 hours. Write and solve a system of equations to determine how many drawings of each type Akira make.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Units will be minutes and count of drawings or "count".

2 hours is 120 minutes.

x = how many b&w
y = how many color

Account for Drawings: x%2By=9
Account for Time: 10x%2B25y=120

Simplify the time account equation, dividing by 5.
2x%2B5y=24

System to Solve:
-------------------------
x+y=9
-------------------------
2x+5y=24
-------------------------

Elimination using 2 times the first equation: 2x%2B2y=18;
Subtract this from the second equation.
%282x%2B5y%29-%282x%2B2y%29=24-18
3y=6
highlight%28y=2%29, which will lead to highlight%28x=7%29.