Evaluate if x =3 and y = -2 x2+2xy−4y

Mathematics

1 answer:

Marysya12 [62]3 years ago

8 0

Answer:

Step-by-step explanation:

With the equation $x^2 + 2xy - 4y$ , we can substitute the values of x = 3 and y = -2 into the equation to find its result.

$(3^2) + (2\cdot3\cdot-2) - (4\cdot-2)\\\\9 + (6\cdot-2) - (-8)\\9 - 12 + 8\\5$

Hope this helped!

You might be interested in

what is perpendicular to y= 3x -9 and passes through the point (3,1)

GREYUIT [131]

$(3,1) , \ \ y= 3x -9 \\ \\ The \ slope \ is :m _{1} =3 \\ \\ If \ m_{1} \ and \ m _{2} \ are \ the \ gradients \ of \ two \ perpendicular \\ \\ lines \ we \ have \ m _{1} \cdot m _{2} = -1 \\ \\3\cdot m_{2}=-1 \ \ /:3\\ \\ m_{2}=-\frac{1}{3}$

$\Now \ your \ equation \ of \ line \ passing \ through \ (3,1) would \ be: \\ \\ y=m_{2}x+b \\ \\1=-\frac{1}{ 3} \cdot3 + b$

$1=-1+b\\ \\ b=1+1\\ \\b=2 \\ \\ y =- \frac{1}{3}x+2$

6 0

3 years ago

I can't find the surface area, is this confusing me.

Fed [463]

<span>Find the area of two sides (Length*Height)*2 sidesFind the area of adjacent sides (Width*Height)*2 sidesFind the area of ends (Length*Width)*2 ends<span>Add the three areas together to find the surface area</span></span>

3 0

2 years ago

Read 2 more answers

John & friends brought 4 bags of popcorn and 3 sodas at the movie for a total of 13.50. At the next movie John & friend

scoray [572]

Answer:

The cost of 5 bags of popcorn and 2 sodas is 14.25 units.

Step-by-step explanation:

We are given the following in the question:

Let x units be the cost of a popcorn bag and y units be cost of soda.

The cost of 4 bags of popcorn and 3 sodas is 13.50.

Thus, we can write the equation: