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3 years ago

Solve the system of equations by graphing. x+y=-7, 2x+y=6

Mathematics

2 answers:

kiruha [24]3 years ago

8 0

Step-by-step explanation:

I hope this is right, I used demos

masya89 [10]3 years ago

3 0

Answer: x=-1 Y = 8

Step-by-step explanation:

you can change it to y = -x-7, y=-2x+6

Then because the both equal “y” they must equal each other.

So -x+7 = - 2x+6

Then solve

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16=5/4(6x+20) what's it's simplest form

Lyrx [107]

Answer:

-6/5

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

If the cost price of 21 articles is equal to the selling price of 18 articles, find the profit percentage

Ksenya-84 [330]

Answer: 14.29%

Step-by-step explanation:

Let C be the cost of 1 article and S the selling price for 1 article. The profit, P, for 1 article would be:

P = S - C

For n articles, the total profit would be

nP = nS - nC

Profit percentage would be (P/S)*100%

---------------------------------------------------------

We know that 21C = 18S: This can be written as C = (18/21)S

P = S - C

P = S - (18/21)S

P = (3/21)S or P=(1/7)S

Profit percentage would therefore be

(P/S)*100%

((1/7)S/S)*100%

(1/7)*100%

= 14.29%

5 0

3 years ago

Find lim h->0 f(9+h)-f(9)/h if f(x)=x^4 a. 23 b. -2916 c. 2916 d. 2925

Svetach [21]

$\displaystyle\lim_{h\to0}\frac{f(9+h)-f(9)}h = \lim_{h\to0}\frac{(9+h)^4-9^4}h$

Carry out the binomial expansion in the numerator:

$(9+h)^4 = 9^4+4\times9^3h+6\times9^2h^2+4\times9h^3+h^4$

Then the 9⁴ terms cancel each other, so in the limit we have

$\displaystyle \lim_{h\to0}\frac{4\times9^3h+6\times9^2h^2+4\times9h^3+h^4}h$

Since h is approaching 0, that means h ≠ 0, so we can cancel the common factor of h in both numerator and denominator:

$\displaystyle \lim_{h\to0}(4\times9^3+6\times9^2h+4\times9h^2+h^3)$

Then when h converges to 0, each remaining term containing h goes to 0, leaving you with

$\displaystyle\lim_{h\to0}\frac{f(9+h)-f(9)}h = 4\times9^3 = \boxed{2916}$

or choice C.

Alternatively, you can recognize the given limit as the derivative of f(x) at x = 9:

$f'(x) = \displaystyle\lim_{h\to0}\frac{f(x+h)-f(x)}h \implies f'(9) = \lim_{h\to0}\frac{f(9+h)-f(9)}h$

We have f(x) = x ⁴, so f '(x) = 4x ³, and evaluating this at x = 9 gives the same result, 2916.

8 0

3 years ago

Can someone please help me with this

Leona [35]

Answer:

The answer is about 13.7 for x

Step-by-step explanation:

Hope this helps.

7 0

3 years ago

What would be the result if a was increased by 25 percent

zloy xaker [14]

Answer: formula - (x/4)+x

Step-by-step explanation:

Since there are no numbers, here is just the formula and what it means :)

(x/4)+x

(btw x is whatever your number is)

so what you need to do first is to divide your number by 4 because 25% is 1/4 of 100%

and then add that number that you just got to your number.

Its a little confusing to say out in words, so here is an example using 24

24/4=6

24+6=30

and heres another example using 50

50/4=12.5

50+12.5=62.5

I hope this helped! <3

6 0

3 years ago