Find two numbers whose product is 80 and whose sum is 18

Let X & Y be the two integers

X+Y=18      Y = 18-X

XY = 80

We can substitute 18-X for Y in the equation XY = 80

X(18-X) = 80

Distributing

18X - X2 = 80

Subtract 80 from both sides so that the equation is equal to 0

-X2 + 18X - 80 = 0

Multiply (or divide by -1 so that the leading coefficient is positive, not negative)

X2 - 18X + 80 = 0

We can factor this quadratic

(X-10)(X-8) = 0

Setting each factor equal to 0 we can solve for X.

X-10 = 0       X-8 = 0

X = 10          X = 8

The two integers are 8 and 10.

Step-by-step explanation:

$9.41

step-by-step explanation:

2 & 7

step-by-step explanation:

he climbs 300 ft/hr at a constant rate. the peak is at 1,500 ft.

when going up, he reaches 600 ft in 2 hours. remember, that he is going in a constant rate. divide 600 with 300:

600/300 = 2

assuming that he takes the same route back (meaning that it's a 1500 ft route back, you can solve.

note also that you are solving when he gets back to 600 ft after he reaches the peak.

first, find the amount of hours it takes to get up the peak. divide the total amount (1500), with the ft/her (300) to get the amount of hours (x):

1500/300 = x

x = 5

it takes jamie 5 hours to get up. now, he is returning down, and reaches 600 (his current destination). remember that he climbs at a constant 300 ft/hr. divide 600 with 300:

600/300 = x

x = 2

now add the two numbers together.

x = 5 + 2 = 7

jamie takes 7 hours to go up the mountain and reach his current position when descending.

(total amount/constant rate) = (time).

remember that it is a constant rate, so in total, when he gets back down the mountain, it will take the same amount of time as when he goes up. the total amount for the round trip is: 5 + 5 = 10.

~