Use subtitution method to solve the problem.
First, change y to the value of x in order to find the exact value of x.
x + y = 4
y = 4 - x
Second, subtitute y with 4 - x from the first equation
y = -x² + 2x + 4
4 - x = -x² + 2x + 4
move all terms to the left side
x² - 2x - x + 4 - 4 = 0
x² - 3x = 0
x(x - 3) = 0
x = 0 or x = 3
Third, now we have 2 values of x. Find the value of y for each of x
For x = 0
y = 4 - x
y = 4 - 0
y = 4
For x = 3
y = 4 - x
y = 4 - 3
y = 1
The solution is (0,4) and (3,1). The answer is option b
Answer:
The original selling price would be $ 515.87 ( approx )
Step-by-step explanation:
Consider the complete question is :
"A sporting goods store manager was selling a ski set for a certain price. The manager offered the markdowns shown, making the one-day sale price of the ski set $325. Find the original selling price of the ski set. It was marked down 10% and 30%"
Suppose x be the original selling price ( in dollars ),
After marking down 10%,
New selling price = x - 10% of x = x - 0.1x = 0.9x
Again after marking down 30%,
Final selling price = 0.9x - 30% of 0.9x
= 0.9x - 0.3 × 0.9x
= 0.9x - 0.27x
= 0.63x
According to the question,
0.63x = 325

Therefore, the original selling price would be $ 515.87.
A i guess i just need points