All categories

2 years ago

Evaluate the algebraic expression 18 + (- 31) =

Mathematics

1 answer:

frosja888 [35]2 years ago

8 0

Answer:

-13

Step-by-step explanation:

You might be interested in

David can paint a fence in ten hours. Alex can paint the same fence in eight hours. If

xxTIMURxx [149]

Answer:

40/9

Step-by-step explanation:

Use the work formula, $\frac{1}{A}$ + $\frac{1}{B}$ = $\frac{1}{T}$ , where A is the amount of time it takes one person, B is the amount of time it takes another person, and T is the time it takes for them to work together.

Plug in the times for David and Alex alone:

$\frac{1}{10}$ + $\frac{1}{8}$ = $\frac{1}{T}$

Find the least common denominator, which is 40.

$\frac{4}{40}$ + $\frac{5}{40}$ = $\frac{1}{T}$

$\frac{9}{40}$ = $\frac{1}{T}$

Cross multiply and solve for T:

9T = 40

T = 40/9

So, if they worked together, it would take them 40/9 hours

3 0

2 years ago

Read 2 more answers

a bathtub is filled with 110 gallons of water. The tub drains at a rate of 5 gallons every 2 minutes. How long will it take befo

Gnesinka [82]

Answer:

It will take 22 minutes

4 0

2 years ago

HELP ME ASAP WILL MARK BRAINLIEST

nataly862011 [7]

Answer:

1912

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

What’s the vertex form of F(x)=x^2+2x-3

kupik [55]

Answer:

$\large\boxed{f(x)=(x+1)^2-4}$

Step-by-step explanation:

$\text{The vertex form of a quadratic equation}\ f(x)=ax^2+bx+c:\\\\f(x)=a(x-h)^2+k\\\\(h,\ k)-\text{vertex}\\=====================================$

$\bold{METHOD\ 1:}\\\\\text{convert to the perfect square}\ (a+b)^2=a^2+2ab+b^2\qquad(*)\\\\f(x)=x^2+2x-3=\underbrace{x^2+2(x)(1)+1^2}_{(*)}-1^2-3\\\\f(x)=(x+1)^2-4\\==============================$

$\bold{METHOD\ 2:}\\\\\text{Use the formulas:}\ h=\dfrac{-b}{2a},\ k=f(k)\\\\f(x)=x^2+2x-3\to a=1,\ b=2,\ c=-3\\\\h=\dfrac{-2}{2(1)}=\dfrac{-2}{2}=-1\\\\k=f(-1)=(-1)^2+2(-1)-3=1-2-3=-4\\\\f(x)=(x-(-1))^2-4=(x+1)^2-4$

4 0

3 years ago

A. Find the vertex form equations (y = a(x - h)2 + k) for the parabolas below.

marta [7]

Answer:

y=-(x+3)^2

y=-x^2-6x-9

Step-by-step explanation:

i uh hope this is correct

hope thia helps <3

3 0

3 years ago