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3 years ago

Work out the value of 3x + 2y when x=4 and y=-5

Mathematics

2 answers:

Kruka [31]3 years ago

5 0

3x + 2y =

3*4 + 2*-5=

12 + -10 = 2

Anon25 [30]3 years ago

4 0

Just substitute the equation with the given

The given are
x = 4 and y = -5
the equation is
3x + 2y
3 (4) + 2 (-5) = 12 - 10 = 2

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If -(x - 1) = 5, find the value of -4x. Show your work.<br> PLEASEEEE !!!

irakobra [83]

Answer: x=-4

Step-by-step explanation:

1. Simplify:

-(x-1)=5 => -x+1=5

Isolate x:

-x=5-1 => -x=4 => x=-4

7 0

3 years ago

You’ve bought a cylindrical thermos 8 in. high with a base 6 in. across. How much coffee can you put in the thermos?

lana66690 [7]

Answer:

3.706 liters

Step-by-step explanation:

Hello

assuming that these measures correspond to the internal measures of the thermos,

we can calculate the volume as, the volume of a cylinder, which is given by

$V=\pi r^{2} h$

where r is the radius of the base, and h the height

also

Diameter=2r

r=Diameter/2

Step 1

let

h=8 in

base = diameter = 6 inch

r=diameter/2

r=6/2 inch,r=3 inch

Step 2

Put the values into the equation

$V=\pi r^{2} h\\V=\pi (3in)^{2} (8 in)\\V=\pi *72 \ in^{3} \\\\V=72\pi\ in^{3} \\\\$

Step 3

Now, the unit (cubic inches) is not an usual unit for measuring coffee, let´s convert cubic inches into liters by knowing

1 inch = 2.54 cm

1 litro = 1000 cubic centimeters

$if\ 1\ inch\ = 2.54\ cm\\(1\ inch)^{3} =(2.54\ cm)^{3}\\\\1\ inch^{3}=16.3870\ cm^{3}$

1 cubic inch = 16.3870 cubic centimeters

$1\ cubic\ inch\ = 16.3870\ cubic\ centimeters\\\\\\72\pi =x?\ cubic\ centimeters\\\\x=\frac{72\pi \cubic \ inch\ \*16.3870 }{1\ cubic\ inch} \\\\x=3706.65\ cubic\ centimeters$

Step 4

Finally, convert cubic centimeters into liters $1000\ cubic\ centimeters =1\ liter \\\\\\3706.65\ cubic\ centimeters = x?\ liters\ centimeters\\\\x=\frac{3706.65 \cubic \ centimeters\ \*1 liter}{1000 cubic centimeters} \\\\x=3706.65\ cubic\ centimeters\\x=3.706 Liters$

I can put 3.706 liters in the thermos

Have a good day

4 0

4 years ago

Percent of change markup discount

vichka [17]

You calculate the markup or markdown in absolute terms (you find by how much the quantity changed), and then you calculate the percent change relative to the original value. So they're really just another form of "increase - decrease" exercises.

Example:

A computer software retailer used a markup rate of 40%. Find the selling price of a computer game that cost the retailer $25.
The markup is 40% of the $25 cost, so the markup is:

(0.40)(25) = 10
Then the selling price, being the cost plus markup, is:

25 + 10 = 35

The item sold for $35.

4 0

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erica [24]

There is a common ratio between the side lengths of Figure A and the side lengths of figure B. The ratio is 3

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zhannawk [14.2K]

Step-by-step explanation: