I need help with this question please I’ll give u brain

Hanna has 44 minutes to get ready for school she spends x minutes getting dress what's an expression that represent the number o

Goshia [24]

44-x= amount of time left

7 0

3 years ago

1-i need to mix 25% mineral spirits to the varnish i am using what ratio of spirit to varnish am i using? 2-if i use 240 ml of v

Ad libitum [116K]

Answer: (a) The ratio of spirit to varnish is 1 : 3

(b) You will need 80 ml of mineral spirits

(c) Ratio = 3 : 2

Step-by-step explanation: (a) If you have to mix 25% mineral spirit to the varnish as required in the question, then the whole solution would effectively contain 25 percent spirit and 75 percent varnish, giving you a hundred percent solution. To express both quantities in ratio can be done as follows;

Ratio = Spirit : Varnish

Ratio = 25 : 75

Ratio = 1 : 3

(b) Next, if you use 240 ml of varnish, this quantity would constitute 75 percent or ratio 3 out of 4 of your total solution. Therefore 240 ml of varnish can be expressed as follows;

240 : x = 3 : 4

Where x is the total solution and the right hand side (3 : 4) expresses the ratio of varnish in relation to the total solution. Hence,

240/x = 3/4

By cross multiplication you now have,

3x = 240 * 4

x = 960/3

x = 320

If x is the total solution which is 320 ml, and varnish constitutes 240 ml, then spirit equals,

Spirit = Total solution - varnish

Spirit = 320 - 240

Spirit = 80.

Therefore, you would need 80 ml of mineral spirits.

(c) Robson's tapestries all measure 1.5 m by 1 m. This can be expressed in whole numbers by first eliminating the decimal. Multiplying both dimensions by 10 results in,

1.5 (10) x 1 (10)

15 x 10

If both measurements can also be expressed as 15 m by 10 m, then reducing to the least terms would result in 3 by 2. That is,

15/5 by 10/5

3 by 2

Expressed as a ratio, this now becomes

Ratio = 3 : 2

6 0

3 years ago

Please Help!!

Genrish500 [490]

Given

$a\sqrt{x+b}+c=d$

we have

$\sqrt{x+b}=\dfrac{d-c}{a}$

Squaring both sides, we have

$x+b=\dfrac{(d-c)^2}{a^2}$

And finally

$x=\dfrac{(d-c)^2}{a^2}-b$

Note that, when we square both sides, we have to assume that

$\dfrac{d-c}{a}>0$

because we're assuming that this fraction equals a square root, which is positive.

So, if that fraction is positive you'll actually have roots: choose

$a=1,\ b=0,\ c=2,\ d=6$

and you'll have

$\sqrt{x}+2=6 \iff \sqrt{x}=4 \iff x=16$

Which is a valid solution. If, instead, the fraction is negative, you'll have extraneous roots: choose

$a=1,\ b=0,\ c=10,\ d=4$

and you'll have

$\sqrt{x}+10=4 \iff \sqrt{x}=-6$

Squaring both sides (and here's the mistake!!) you'd have

$x=36$

which is not a solution for the equation, if we plug it in we have

$\sqrt{x}+10=4 \implies \sqrt{36}+10=4 \implies 6+10=4$

Which is clearly false

7 0

3 years ago

Find the exponential function that passes through the points (2,80) and (5,5120)

juin [17]

Answer:

y = 5·4^x

Step-by-step explanation:

If you have two points, (x1, y1) and (x2, y2), whose relationship can be described by the exponential function ...

y = a·b^x

you can find the values of 'a' and 'b' as follows.

Substitute the given points:

y1 = a·b^(x1)

y2 = a·b^(x1)

Divide the second equation by the first:

y2/y1 = ((ab^(x2))/(ab^(x1)) = b^(x2 -x1)

Take the inverse power (root):

(y2/y1)^(1/(x2 -x1) = b

Use this value of 'b' to find 'a'. Here, we have solved the first equation for 'a'.

a = y1/(b^(x1))

In summary:

b = (y2/y1)^(1/(x2 -x1))
a = y1·b^(-x1)

__

For the problem at hand, (x1, y1) = (2, 80) and (x2, y2) = (5, 5120).

b = (5120/80)^(1/(5-2)) = ∛64 = 4

a = 80·4^(-2) = 80/16 = 5

The exponential function is ...

y = 5·4^x

3 0

3 years ago

The equation y ̂=844.697x^2+3723.485x-13,650 models the annual profits of a new business, where x is the number of years since t

julsineya [31]

The answer is $37,923

<span>y = 844.697x^2 + 3723.485x - 13,650
x - number of years
y - the annual profit

If x = 8, the annual profit y is:
y = </span>844.697 * 8^2 + 3723.485 * 8 - 13,650
y = 844.697 * 64 + 29,787.88 - 13,650
y = 54,060.608 + 16,137.88
y = 37,922.728 ≈ 37,923

5 0

4 years ago