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3 years ago

Evaluate the numerical expression -12.2 - 6.4 divided 0.8

Mathematics

1 answer:

liraira [26]3 years ago

3 0

Answer:

-23.25

Step-by-step explanation:

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If 4f(x)+f(5-x)=x2<br><br> What is f(x)?

aksik [14]

We are given that $4f(x)+f(5-x)=x^2$ .

Substitute x with 5-x, then the above equation becomes:

$4f(5-x)+f(5-(5-x))=(5-x)^2$ , that is

$4f(5-x)+f(x)=(5-x)^2$

So, we have the following system of equations:

i) $4f(x)+f(5-x)=x^2$
ii) $4f(5-x)+f(x)=(5-x)^2$

multiply the first equation by -4, so that we eliminate f(5-x)'s

i) $-16f(x)-4f(5-x)=-4x^2$
ii) $4f(5-x)+f(x)=(5-x)^2$

adding the 2 equations side by side we have:

$-15f(x)=-4x^2+(5-x)^2$

expanding the binomial, and collecting same terms we have:

$-15f(x)=-4x^2+(25-10x+x^2)$

$-15f(x)=-3x^2-10x+25$

dividing by -5:

$3f(x)=\frac{3}{5}x^2+2x-5$

dividing by 3:

$\displaystyle{f(x)= \frac{1}{5}x^2+ \frac{2}{3}x-\frac{5}{3}$

Answer: $\displaystyle{f(x)= \frac{1}{5}x^2+ \frac{2}{3}x-\frac{5}{3}$

6 0

3 years ago

Ship A sights ship B on a bearing of 308°. What is the bearing of A from B?

MatroZZZ [7]

Answer:

128°

Step-by-step explanation:

the answer is 128° i explained it as i could in the diagram hope you understand

6 0

3 years ago

Alik [6]

Answer:

2cm of Rainfall

Step-by-step explanation:

When the no. of mosquitoes is the highest the slope of graph will be zero

so if we differentiate this function and equate to zero we can find the rainfall amount that gives maximum number of mosquitoes in centimetres.

m(x)= -x²+4x

differentiate

d(x)/d(m(x))= -2x+4

equate to zero

-2x+4=0

2x=4

x=2

answer: 2 cm of rain

6 0

3 years ago

How do do I find how many times faster is the cheetah over a human? Number 15

levacccp [35]

I thinks it is b .i hope this help you

5 0

3 years ago

25 is what percent of 64

Flauer [41]

Make a proportion to find the percent:
25/64 = x/100
Multiply 25 and 100, then divide that answer by 64. Then add a percent symbol.

25*100 =2500
2500/64 = 39.0625
39.0625%

7 0

3 years ago