7. *Eynee decided to give her little sister 30% of what she earned this week at her job. If

jarptica [38.1K]

First we'll do two basic steps. Step 1 is to subtract 18 from both sides. After that, divide both sides by 2 to get x^2 all by itself. Let's do those two steps now

2x^2+18 = 10
2x^2+18-18 = 10-18 <<--- step 1
2x^2 = -8
(2x^2)/2 = -8/2 <<--- step 2
x^2 = -4

At this point, it should be fairly clear there are no solutions. How can we tell? By remembering that x^2 is never negative as long as x is real.

Using the rule that negative times negative is a positive value, it is impossible to square a real numbered value and get a negative result.

For example
2^2 = 2*2 = 4
8^2 = 8*8 = 64
(-10)^2 = (-10)*(-10) = 100
(-14)^2 = (-14)*(-14) = 196

No matter what value we pick, the result is positive. The only exception is that 0^2 = 0 is neither positive nor negative.

So x^2 = -4 has no real solutions. Taking the square root of both sides leads to

x^2 = -4
sqrt(x^2) = sqrt(-4)
|x| = sqrt(4)*sqrt(-1)
|x| = 2*i
x = 2i or x = -2i
which are complex non-real values

5 0

3 years ago

Answers options are 6/26 8/18 14/12 14/26 Pls help

prohojiy [21]

Answer:

14/26

Step-by-step explanation:

6+8=14

14+12=26

6 0

3 years ago

A car travels 120 miles in 2.5 hours (with a constant speed). What is the car's

kipiarov [429]

Answer:

48

Step-by-step explanation:

120 divided by 2.5 = 40

5 0

3 years ago

Read 2 more answers

In triangle ABC, cos A =

nikitadnepr [17]

The other expression that has a value of $\frac{7}{25}$ is A) sin B.

Step-by-step explanation:

Step 1:

$sin\theta = \frac{oppositeside}{hypotenuse} ,$ $cos\theta = \frac{adjacentside}{hypotenuse} ,$ $tan \theta = \frac{opposite side}{adjacent side} .$

For angle B, the opposite side measures 7 units, the adjacent side measures 24 units and the hypotenuse measures 25 units.

$sinB= \frac{oppositeside}{hypotenuse} = \frac{7}{25} ,$ $tan B = \frac{opposite side}{adjacent side} = \frac{7}{24} ,$ $cosB = \frac{adjacentside}{hypotenuse} = \frac{24}{25}.$

Step 2:

For angle A, the opposite side measures 24 units, the adjacent side measures 7 units and the hypotenuse measures 25 units.

$tan A = \frac{opposite side}{adjacent side} = \frac{24}{25} .$

Step 3:

tan C cannot be determined as C is the right angle. The opposite side and hypotenuse of the triangle would be the same.

So sin B also has a value of $\frac{7}{25}.$ This is option A.

7 0

3 years ago

HELP pls!!

Rudiy27

<h3>Answer: Choice B) x = 65, y = 10</h3>

====================================================

Work Shown:

The upper pair of angles 60 degrees and (2x-y) degrees are supplementary angles. This is because of the parallel lines. Note how they are same side interior angles. Therefore, (2x-y) and 60 combine to 180 degrees like so

(2x-y)+60 = 180

2x-y = 180-60 ... subtract 60 from both sides

2x-y = 120 ... call this equation 1

-------

Similarly, (2x+y) and 40 also combine to 180

(2x+y) + 40 = 180

2x+y = 180-40 ... subtract 40 from both sides

2x+y = 140 ... call this equation 2

------

Line up equation 1 and equation 2. Then add straight down

$\ \ \ 2x-y = 120\\+ 2x+y = 140\\\hrule\\\\\\ \ \ \ 4x+0y = 260\\\\$

That becomes 4x = 260 which solves to x = 65 when you divide both sides by 4.

------

If x = 65, then,

2x-y = 120

2(65)-y = 120

130 - y = 120

-y = 120-130

-y = -10

y = 10

or

2x+y = 140

2(65)+y = 140

130+y = 140

y = 140-130

y = 10

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Either way end up with x = 65 and y = 10

4 0

3 years ago