X + y = 15
xy = -312
x + y = 15
x - x + y = -x + 15
y = -x + 15
xy = -312
x(-x + 15) = -312
x(-x) + x(15) = -312
-x² + 15x = -312
-x² + 15x + 312 = 0
-1(x²) - 1(-15x) - 1(312) = 0
-1(x² - 15x + 312) = 0
-1 -1
x² - 15x + 312 = 0
x = -(-15) ± √((-15)² - 4(1)(312))
2(1)
x = 15 ± √(225 - 1248)
2
x = 15 ± √(-1023)
2
x = 15 ± 31.984i
2
x = 7.5 ± 15.992
x = 7.5 + 15.992 or x = 7.5 - 15.992
x = 23.492 or x = -8.492
x + y = 15
23.492 + y = 15
- 23.492 - 23.492
y = -8.492
(x, y) = (23.492, -8.492)
or
x + y = 15
-8.492 + y = 15
+ 8.492 + 8.492
y = 23.492
(x, y) = (-8.492, 23.492)
The two numbers that add up to 15 and mutliply to -312 are -8.492 and 23.492.
Answer:
5301
Step-by-step explanation:
There are 9 companies that needed to print 589 coupons each. Multiply the two numbers:
9 * 589 = 5301
max is at vertex
in form 
the x value of the vertex is 
given, 
a=6, b=0
the x value of the vertex is -0/(2*6)=0
the y value is 
so vertex is at (0,-1)
since the value of a is positive, the parabola opens up and the vertex is a minimum value of the function
therefore that value is the smallest value the function can be
domain=numbesr you can use for x
range=numbesr you get out of inputting the domain
domain=all real numbers
range is {y | y≥-1} since y=-1 is the minimum
8
round each number to the nearest 10, then
640 ÷ 80 = 8 ← estimate
Total distance traveled = 4 + 6 = 10 miles
Total time = 15 + 25 = 40 minutes
Speed = 10 miles ÷ 40 minutes = 0.25 mph
