F(x) =x^2+6x and g(x)=7-x find (f-g)(x) and (f-g)(9)

Mathematics

1 answer:

frez [133]3 years ago

7 0

F(x)=x²+6x
g(x)=7-x

(f-g)(x) means that f(x)-g(x), so
f(x)-g(x)
=x²+6x-7+x
Combining like terms
x²+6x+x-7
=x²+7x-7, so (f-g)(x)=x²+7x-7
Next,
(f-g)(x)
=x²+7x-7
(f-g)(9)
=(9)²+7(9)-7
=81+63-7
=144-7
=137, so (f-g)(9)=137. Hope it help!

You might be interested in

A dog owner is told by the veterinarian that his dog, Max, is overweight and needs to lose 4 to 5 pounds in order to live a heal

hodyreva [135]

This is a linear function, of the kind y = mx + b

where x is the number of visit, b is the weight when x = 0, and m is the predicted change of weight for every visit.

m = - 4 ounces / visit, which must be converted to pounds (the negative sign indicates that the change is a decrease)

1 lb = 16 ounces = 4 ounces = 0.25 lb

Then m = - 0.25 lb / visit.

Now, for x = 1, y = 126 => 126 = - 0.25(1) + b => b = 126 + 0.25 = 126.25

Then the function is y = 126.25 - 0.25x

Now round to the nearest tenth:

y = 126.3 - 0.3x

Answer: y = 126.3 - 0.3x

6 0

3 years ago

(PLEASE HELP!!!!)Mario has money in savings. He also has a job with hourly pay. After

Olin [163]

Answer:

X = savings, p= pay per hour

X+4p = 86 - - - - (1)

X+6p=104 - - - - - (2)

Re arrange equation (1)

X=86-4p-----(3)

Substitute (3) in (2)

86-4p +6p=104

86+2p=104. (subtract 86 from both side)

2p = 18. (divide by 2 from both side)

Then p =$9

By substitute in equation (1)

X = $50

5 0

2 years ago

The mean rent of a 3-bedroom apartment in Orlando is $1300. You randomly select 10 apartments around town. The rents are normall

lana [24]

Answer:

96.49% probability that the mean rent is more than $1100

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .