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Marina CMI [18]

3 years ago

6

Lupe uses 7.8 pints of white paint and blue paint to paint her bedroom walls. 3 4 of this amount is white paint, and the rest is

blue paint. How many pints of blue paint did she use to paint her bedroom walls?

1 answer:

Leto [7]3 years ago

5 0

41.8 pints or 11.2 pints

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I can’t figure it out?

lara [203]

Answer:

D, $10.47

Step-by-step explanation:

3 0

4 years ago

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Which of these expressions is equal to 3(30 - p)?

slava [35]

Answer:

$(3 \times 30) - (3 \times p)$

Answer B is correct

Step-by-step explanation:

$3(30 - p) \\ (3 \times 30) - (3 \times p)$

<h3>hope this helps you</h3>

can I have the brainliest please?

5 0

3 years ago

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The sum of Two numbers is 9. The<br> sum of the squares of the numbers is<br> 41. Find the numbers.

Tju [1.3M]

Answer:

4 and 5

Step-by-step explanation:

Assuming your 2nd sentence should be: "The sum of the squares of the two numbers is 41"

X + Y = 9 {equation 1}

X² + Y² = 41 {equation 2}

from equation 1: y = 9-x

Substitute that into equation 2

x² + (9-x)² = 41

x² + 81 - 18x + x²= 41

2x² - 18x + 40 = 0

We can factor out a 2

x² - 9x + 20 = 0

(x-5)(x-4) = 0

x = 5 or 4

checking

Your two numbers are 4 and 5

4² + 5²

= 16 + 25

= 41

3 0

3 years ago

X^2 + 4x - 9 = (x + a)^2 + b<br><br> Find the value of a and the value of b

REY [17]

Answer:

<h2>a = 2, b = -13</h2>

Step-by-step explanation:

We have three ways.

$(a+b)^2=a^2+2ab+b^2\qquad(*)$

$\bold{1.}\\\\x^2+4x-9=x^2+2(x)(2)-9=\underbrace{x^2+2(x)(2)+2^2}_{(*)}-2^2-9\\\\=(x+2)^2-4-9=(x+2)^2-13\\\\x^2+4x-9=(x+a)^2+b\\\Downarrow\\(x+2)^2-13=(x+a)^2+b\Rightarrow \boxed{\bold{a=2, b=-13}}$

$\bold{2.}\\\\\underbrace{(x+a)^2}_{(*)}+b=x^2+2ax+a^2+b\\\\x^2+4x-9=x^2+2ax+(a^2+b)\Rightarrow 4=2a\ \text{and}\ -9=a^2+b\\\\4=2a\qquad\text{divide both sides by 2}\\\\\dfrac{4}{2}=\dfrac{2a}{2}\\\\2=a\to \boxed{\bold{a=2}}\\\\\text{Substitute to the second equation:}\\\\-9=2^2+b\\\\-9=4+b\qquad\text{subtract 4 from both sides}\\\\-9-4=4-4+b\\\\-13=b\to \boxed{\bold{b=-13}}$

$\bold{3.}\\\\(x+a)^2+b-\text{it's a vertex form of an equation of a parabola}\\\\\text{Let}\ y=a(x-h)^2+k\ -\ \text{the euation of a parabola}\ y=ax^2+bx+c.\\\\\text{Then}\ h=\dfrac{-b}{2a},\ k=\dfrac{-(b^2-4ac)}{4a}\\\\x^2+4x-9\to a=1,\ b=4,\ c=-9\\\\h=\dfrac{-4}{2(1)}=\dfrac{-4}{2}=-2\\\\k=\dfrac{-(4^2-4(1)(-9))}{4(1)}=\dfrac{-(16+36)}{4}=\dfrac{-42}{4}=-13\\\\\text{Therefore}\\\\x^2+4x-9=(x+a)^2+b\\\\(x-(-2))^2+(-13)=(x+a)^2+b\\\\(x+2)^2-13=(x+a)^2+b\to\boxed{\bold{a=2,\ b=-13}}$

4 0

3 years ago

How many different two-letter passwords can be formed from the letters upper a comma upper b comma upper c comma upper d comma

zmey [24]

This kind of exercises are solved by counting the choices you have at every step.

We have five possible letters: A,B,C,D and E. We want to form a two-letter password without repetitions. This means that we have five choices for the first letter: in can be any of the five letters, because we have no restrictions so far.

Now, assume we have chosen a particular letter to be the first one. How many choices do we have for the second letter? Well, we're told that we can't repeat letters, so we have four choices. In fact, once the first letter is fixed, the second letter can be any of the five, except the one we fixed as first.

For example, if the first letter is C, we have the following four choices: CA, CB, CD, CE, since we're not allowed to choose CC, because there are repeating letters.

So, we have four choice for the second letter, for each of the five choices we have for the first letter. This leads to a total of 20 passwords:

First letter A: AB, AC, AD, AE

First letter B: BA, BC, BD, BE

First letter C: CA, CB, CD, CE

First letter D: DA, DB, DC, DE

First letter E: EA, EB, EC, ED

5 0

3 years ago