All categories

3 years ago

8:54 a.m.

1 answer:

5 0

Hello,

The two lights flash at the same time every 18 min
at 8:00 h=480 min =480+0*36
at 8:36 h=516 min =480+1*36
...
54 is not divisible by 36
60+12=72 = 2*36 yes
60+24=84 not
120+24=4*36 yes
180+18=198 not

So 2 times are correct 9:12 and 10:24
Answer G

You might be interested in

Simplify: -10 - 90x + 6x - 60

antoniya [11.8K]

Answer:

- 84x - 70

Step-by-step explanation:

We want to combine like terms:

-10 - 90x + 6x - 60

We can see (-10) and (-60) are both regular constants so:

- 10 - 60 = - 70

Then (-90x) and (+ 6x):

6x - 90x = - 84x

- 84x - 70

4 0

3 years ago

Solve this equation for x: 2x^2 + 12x - 7 = 0

zhannawk [14.2K]

Answer:

x=0.5355 or x=-6.5355

First step is to: Isolate the constant term by adding 7 to both sides

Step-by-step explanation:

We want to solve this equation: $2x^2 + 12x - 7 = 0$

On observation, the trinomial is not factorizable so we use the Completing the square method.

Step 1: Isolate the constant term by adding 7 to both sides

$2x^2 + 12x - 7+7 = 0+7\\2x^2 + 12x=7$

Step 2: Divide the equation all through by the coefficient of $x^2$ which is 2.

$x^2 + 6x=\frac{7}{2}$

Step 3: Divide the coefficient of x by 2, square it and add it to both sides.

Coefficient of x=6

Divided by 2=3

Square of 3= $3^2$

Therefore, we have:

$x^2 + 6x+3^2=\frac{7}{2}+3^2$

Step 4: Write the Left Hand side in the form $(x+k)^2$

$(x+3)^2=\frac{7}{2}+3^2\\(x+3)^2=12.5\\$

Step 5: Take the square root of both sides and solve for x

$x+3=\pm\sqrt{12.5}\\x=-3\pm \sqrt{12.5}\\x=-3+ \sqrt{12.5}, $ or $x= -3- \sqrt{12.5}\\$x=0.5355 or x=-6.5355$

6 0

3 years ago

Which equation represents the circle described? (in picture)

Sedaia [141]

You are right. In circle equation we have =r² so the correct answer will be C od D. But we have to calculate the center of a circle.

$x^2+y^2-8x-6y+24=0\quad|-24\\\\(x^2-8x)+(y^2-6y)=-24$

Complete the square:

$x^2-8x+a^2\implies a=\dfrac{8x}{2x}=4\implies x^2-8x+4^2\\\\\\y^2-6y+b^2\implies b=\dfrac{6y}{2y}=3\implies y^2-6y+3^2$

And we have:

$(x^2-8x)+(y^2-6y)=-24\\\\(x^2-8x+4^2)-4^2+(y^2-6y+3^2)-3^2=-24\\\\
(x-4)^2+(y-3)^2-16-9=-24\\\\(x-4)^2+(y-3)^2-25=-24\quad|+25\\\\\boxed{(x-4)^2+(y-3)^2=1}$

So the answer is C (the same left side of equation).

6 0

3 years ago

I'm really lost on this problem

Alenkinab [10]

Since you need a little bit of trigonometry to solve this problem,
I'm pretty sure you've had a little bit of trigonometry in class before
you were assigned to solve this problem.

-- The shaded triangle comes from taking the equilateral triangle and
either folding it in half or cutting it in half.

-- The base that the new triangle is standing on is 1/2 the base of the
equilateral triangle, so it's 7 cm long.

-- The acute angle at the right end of the base is the same as it was in
the equilateral triangle . . . 60 degrees.

-- The tangent of 60 degrees is (opposite side)/(adjacent side) = x / 7 cm

tan(60) = x/7

-- Multiply each side of this little equation by 7 : 7 tan(60) = x

If you don't have the tangent of 60 degrees in your pocket, you can
find it with your calculator. Multiply it by 7, and Shazam, you know 'x' .

5 0

3 years ago

Fun question: Which Disney character is your favorite?

Vlada [557]

Answer:

Belle is my fav.

Step-by-step explanation:

She loves to read books like me and I hate people who always go out there and try to impress me with something.

5 0

3 years ago