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3 years ago

Just number 7 would be fine but if you could also number 8 would help a lot

Mathematics

2 answers:

BlackZzzverrR [31]3 years ago

8 0

Answer:

7. r = -5

8. x = -1

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Equality Properties

Step-by-step explanation:

Step 1: Define

r + 2 - 8r = -3 - 8r

Step 2: Solve for r

Combine like terms: -7r + 2 = -3 - 8r
Add 8r to both sides: r + 2 = -3
Subtract 2 on both sides: r = -5

Step 3: Check

Plug in r into the original equation to verify it's a solution.

Substitute in r: -5 + 2 - 8(-5) = -3 - 8(-5)
Multiply: -5 + 2 + 40 = -3 + 40
Add: -3 + 40 = -3 + 40
Add: 37 = 37

Here we see that 37 does indeed equal 37.

∴ r = -5 is a solution of the equation.

Step 4: Define equation

-4x = x + 5

Step 5: Solve for x

Subtract x on both sides: -5x = 5
Divide -5 on both sides: x = -1

Step 6: Check

Plug in x into the original equation to verify it's a solution.

Substitute in x: -4(-1) = -1 + 5
Multiply: 4 = -1 + 5
Add: 4 = 4

Here we see that 4 does indeed equal 4.

∴ x = -1 is a solution of the equation.

djverab [1.8K]3 years ago

8 0

Yeah I think whatever that dude just said was right

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$\begin{aligned} \| u \| &= \sqrt{{7}^{2} + {(-2)}^{2}} \\ &= \sqrt{53} \end{aligned}$ .

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Let $\theta$ denote the angle between these two vectors. By the property of dot products:

$\begin{aligned} \cos(\theta) &= \frac{u \cdot v}{\|u\| \, \| v \|} \\ &= \frac{(-11)}{(\sqrt{53})\, (\sqrt{5})} \\ &= \frac{(-11)}{\sqrt{265}}\end{aligned}$ .

Apply the inverse cosine function ${\rm arccos}$ to find the value of this angle:

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8 0

2 years ago

Just number 7 would be fine but if you could also number 8 would help a lot​

Just number 7 would be fine but if you could also number 8 would help a lot