Question

Given constants a and b such that x2 + ax + b has factors (x + 7) and (x + 2) what is a?

dezoksy [38]

Answer:

a=9 , b=14

Step-by-step explanation:

Just do the operation (x+7)(x+2)

x(x)+x(2)+7(x)+7(2)

x^2+2x+7x+14

x^2+9x+14

So a=9 and b=14

8 0

2 years ago

Help me please ;(

sladkih [1.3K]

While it says not to state it, I will state which one is which, just for clarification.

Linear Pattern: A person is paid $10 for every hour they work. Before they start working, they are given an additional $5. They receive no raises in their pay.
This is linear because the pay is constant, and they aren't receiving any additional money. The equation for this would be y = 10x+5, x is the amount of hours they work.

Non-Linear Pattern: A person is paid $10 for every hour they work. Before they start working, they get are given an additional $5. For every 30 minutes they work after hour 4, they receive a $1 raise.
This is non-linear because the pay, after a certain amount of time, would go up, and the graph would soon start going higher after hour 4.

An ordered pair for the linear would be: (5, 55)
After working 5 hours, they would have $55.

An ordered pair for the non-linear would be (5, 56)
After working for 5 hours, they would have $56.

5 0

3 years ago

F (x) = cx + 3

algol13

If f(1) = 1 that means c is -2 because when you substitute x = 1 and when c = -2, you'll get f(1) = -2(1)+3 = -2+3 = 1

So the constant c is -2 and that means the value of f(-4) is

f(-4)=-2(-4)+3=8+3=11

Thus, the value of f(-4) is 11.

About why does "c" have to be -2, here's the proof.

Given y = f(x), therefore.

y=cx+3

Since when x = 1 and y = 1, then Substitute x = 1 and y = 1, thus 1 = c+3

1 - 3 = c and therefore, -2 = c #

So this is the proof that c = -2

4 0

3 years ago

How do you integrate arctan(x dx? i think that if you simplify the integral you get:?

Temka [501]

Integration by parts will help here. Letting $u=\arctan x$ and $\mathrm dv=\mathrm dx$ , you end up with $\mathrm du=\dfrac{\mathrm dx}{1+x^2}$ and $v=x$ . Now

$\displaystyle\int\arctan x\,\mathrm dx=uv-\int v\,\mathrm du$
$\displaystyle\int\arctan x\,\mathrm dx=x\arctan x-\int\frac x{1+x^2}\,\mathrm dx$

For the remaining integral, setting $y=1+x^2$ gives $\dfrac{\mathrm dy}2=x\,\mathrm dx$ , so

$\displaystyle\int\frac x{1+x^2}\,\mathrm dx=\frac12\int\frac{\mathrm dy}y=\frac12\ln|y|+C=\frac12\ln(1+x^2)+C$

Putting everything together, you end up with

$\displaystyle\int\arctan x\,\mathrm dx=x\arctan x-\frac12\ln(1+x^2)+C$

6 0

3 years ago

You're going on a 1211-mile trip, and your car gets about 29 miles per gallon. Gas prices along your route average $3.40. Estima

Vilka [71]

Answer:

Using the estimate:

The car has to go for 1,200 miles but it consumes a gallon of gasoline for every 30 miles. The number of gallons it will need is therefore:

= 1,200 / 30

= 40 gallons

Each gallon costs $3.00 so the total cost is:

= 40 * 3

= $120

Without using the estimate:

The car has to go for 1,211 miles but it consumes a gallon of gasoline for every 29 miles. The number of gallons it will need is therefore:

= 1,211 / 29

= 41.76 gallons

Each gallon costs $3.40 so the total cost is:

= 41.76 * 3.40

= $‭141.98

Using the estimate provides a lower cost of gasoline for the trip. 

3 0

3 years ago