Equation #1: x+y=40
Equation #2: 7x+4y=193
Monica bought 11 red bricks.
Step-by-step explanation:
Given,
Cost of one red brick = $7
Cost of one gray brick = $4
Total spent on bricks = $193
Total bricks bought = 40
Let,
x represents the number of red bricks bought.
y represents the number of gray bricks bought.
What is the system that models this situation?
Equation #1: x+y=40
Equation #2: 7x+4y=193
How many red bricks did Monica purchase?
Multiplying Eqn 1 by 4
[tex]4(x+y=40)\\4x+4y=160\ \ \ Eqn\ 3[/tex]
Subtracting Eqn 3 from Eqn 2
[tex](7x+4y)-(4x+4y)=193-160\\7x+4y-4x-4y=33\\3x=33[/tex]
Dividing both sides by 3
[tex]\frac{3x}{3}=\frac{33}{3}\\x=11[/tex]
Monica bought 11 red bricks.
Keywords: linear equation, elimination method
Learn more about elimination method at:
#LearnwithBrainly
