Solve: 7 = x + 12 A) -19 B) -5 C) 4 D) 5

Mathematics

1 answer:

DaniilM [7]3 years ago

8 0

Hello, there! :)

Answer:

x=-5

B. -5

*The answer must have a negative sign.*

Step-by-step explanation:

Definition of subtraction property of equality.

Subtraction property of equality is subtracting the same number from both sides of an equation does not change the equation.

$a-c=b-c$

First, you had to switch sides.

$x+12=7$

Then, you subtract by 12 from both sides of an equation.

$x+12-12=7-12$

And finally, simplify or solve.

$7-12=-5$

$x=-5$

Hope this helps!

Thanks!

-Charlie

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1. A boat is 18 ft away from a point perpendicular to the shoreline. A person stands at a point down the shoreline so that a 68°

slega [8]

Answer:

19.4 feet

Step-by-step explanation:

When calculating distances using perpendicular angles, we use trig functions such as Sin, Cos, and Tan.

Sine is defined in a perpendicular triangle as the ratio of the opposite side to the angle over the hypotenuse.
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Tangent is defined in a perpendicular triangle as the ratio of the opposite side over the adjacent side.

Because our angle and know side value are across from each other and we need to know the hypotenuse, we chose to use Sine.

We set up the equation $sin (68) = \frac{18}{h}$ .

We isolate h by multiplying h across the equal sign and dividing sin (68) across as well. $sin (68) = \frac{18}{h}\\hsin (68) = \frac{18}{h}*h\\hsin (68) = 18\\\frac{hsin (68)}{sin (68)} =\frac{18}{sin (68)} \\$