Answer:
Step-by-step explanation:
we have

This is the equation of a vertical parabola open downward
The vertex represent a maximum
Convert the quadratic equation into vertex form
step 1
Factor -2

step 2
Complete the square


step 3
Rewrite as perfect squares
----> equation in vertex form
The vertex is the point (1,5)
420 is the least common multiple for 21, 28, 35
Answer:
x=63
Step-by-step explanation:
55+62+x=180
117+x=180
180-117=63
x=63
Range: lowest number subtracted from highest number
105.40 - 27.50 = $77.90
380 - 18% of 380
= 380 - (18/100)×380
= 380 - 68.4
= 311.6