Evaluate the expression

Mathematics

2 answers:

rodikova [14]2 years ago

8 0

Answer:

-5

Step-by-step explanation:

1/4 ( -5 + 5(-3))

Using PEMDAS

Multiply inside the parentheses

1/4 ( -5 + -15)

Add inside the parentheses

1/4( -20)

Multiply

-5

Natalka [10]2 years ago

6 0

Answer: -5

Step-by-step explanation:

Multilpy $\frac{1}{4}$ x (-5 + 5 x (3)

Calculate $\frac{1}{4}$ x (-5 - 15)

- $\frac{1}{4}$ x 20

= -5

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Evaluate 10x+18 when x=5

AfilCa [17]

The answer is 68 because 10 multiplied by 5 is 50 plus 18 is 68

5 0

2 years ago

If x+1/x= 3, then prove that m^5+1/m^5= 123

alina1380 [7]

9514 1404 393

Explanation:

We can start with the relations ...

$\displaystyle\left(x+\frac{1}{x}\right)^3=\left(x^3+\frac{1}{x^3}\right)+3\left(x+\frac{1}{x}\right)\\\\\left(x+\frac{1}{x}\right)^5=\left(x^5+\frac{1}{x^5}\right)+5\left(x^3+\frac{1}{x^3}\right)+10\left(x+\frac{1}{x}\right)\\\\\textsf{From these, we can derive ...}\\\\x^5+\frac{1}{x^5}=\left(x+\frac{1}{x}\right)^5-5\left(\left(x+\frac{1}{x}\right)^3-3\left(x+\frac{1}{x}\right)\right)-10\left(x+\frac{1}{x}\right)$

$\displaystyle x^5+\frac{1}{x^5}=\left(x+\frac{1}{x}\right)^5-5\left(x+\frac{1}{x}\right)^3+5\left(x+\frac{1}{x}\right)\right)\\\\x^5+\frac{1}{x^5}=3^5 -5(3^3)+5(3)\\\\=((3^2-5)3^2+5)\cdot3=(4\cdot9+5)\cdot3=(41)(3)\\\\=\boxed{123}$