•If x = 5 and y = -2, what is the value of 3x2 – 2xy + 4y2?

Mathematics

2 answers:

Luba_88 [7]3 years ago

7 0

Answer:

The value of the equation is 111.

Step-by-step explanation:

Refresh if you cannot see below.

$3x^2-2xy+4y^2\\[Substitute the values.]3(5)^2-2(5)(-2)+4(-2)^2\\[According to PEMDAS, evaluate exponents (there is no evaluating in the parenthesis in the equation) next.]3(25)-2(5)(-2)+4(4)\\[According to PEMDAS, evaluate multiplication (there is no division) next.]75-(-20)+16\\[Subtracting a negative will grant you a positive.]75+20+16\\[Add 75 and 20.]95+16\\[Add 95 and 16.]111$

abruzzese [7]3 years ago

4 0

Step-by-step explanation:

6=2(-2)x5+4(-2)×2

6=-4×5-8×2

6=-20-8×2

6=-20-16

6=-36

You might be interested in

Use the definition of continuity and the properties of limit to show that the function f(x)=x sqrtx/ (x-6)^2 is continuous at x=

jasenka [17]

Answer:

The function $\\ f(x) = \frac{x*\sqrt{x}}{(x-6)^{2}}$ is continuous at x = 36.

Step-by-step explanation:

We need to follow the following steps:

The function is:

$\\ f(x) = \frac{x*\sqrt{x}}{(x-6)^{2}}$

The function is continuous at point x=36 if:

The function $\\ f(x)$ exists at x=36.
The limit on both sides of 36 exists.
The value of the function at x=36 is the same as the value of the limit of the function at x = 36.

Therefore:

The value of the function at x = 36 is:

$\\ f(36) = \frac{36*\sqrt{36}}{(36-6)^{2}}$

$\\ f(36) = \frac{36*6}{900} = \frac{6}{25}$

The limit of the $\\ f(x)$ is the same at both sides of x=36, that is, the evaluation of the limit for values coming below x = 36, or 33, 34, 35.5, 35.9, 35.99999 is the same that the limit for values coming above x = 36, or 38, 37, 36.5, 36.1, 36.01, 36.001, 36.0001, etc.

For this case:

$\\ lim_{x \to 36} f(x) = \frac{x*\sqrt{x}}{(x-6)^{2}}$