Step 1. Simplify
7x^2 - 8x - 4 - 2x^2 + 3x + 5 + 5x^2 - 10x - 8
Step 2. Collect like terms
(7x^2 - 2x^2 + 5x^2) + (-8x + 3x - 10x) + (-4 + 5 - 8)
Step 3. Simplify
10x^2 - 15x - 7
Since we will be completing the square we need to isolate the x
y-5 = 2x^2 -4x
now we the coefficient of the x^2 to equal 1 so we take 2 as common factor
y-5 = 2(x^2 -2x)
now we'll make it perfect square by adding 2 to both sides
y-5+2=2(x^2-2x+1)
now simplify and convert the right side to squared expression
y-3 = 2(x-1)^2
now isolate the y
y = 2(x-1)^2 +3 that's it
It should be |-80+15|=65 units because absolute value makes it positive.
Answer:
1.75
Step-by-step explanation:
Low- 81
Q1-82.5
Median- 83.5
Q3-84
High- 85