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3 years ago

Loft insulation reduces annual heating costs by 20%.

Mathematics

1 answer:

Bond [772]3 years ago

3 0

Answer:

Without isolation annual cost would be 650$

Step-by-step explanation:

Without isolation annual cost is named x and it's worth 100%

With isolation annual cost is 520$ and it's worth (100%-20%) = 80%

Now we will make proportion

x : 520 = 100 : 80

When we multiply external and internal members we get

80 x = 100 · 520 => x = 100 · 520/80 = 650$

x = 650$

God with you!!!

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adult tickets to the fall play cost $8 and student tickets cost $4. the drama class sold 20 more adult tickets than student tick

andriy [413]

let us repersent the number of student tickets, then 's + 20' is repersenting the number of adult tickets.

The equation for the total tickets can be experssed as the following:

4.00 * s + 8.00 * ( s + 20 ) = 880.00

solving for 's=60', there were 60 student tickets.

60 + 20 = 80

there were 80 adult tickets.

Hope helps!-Aparri

5 0

3 years ago

Alexis bought a CD player. She does not remember the price, but she does know that the 5% sales tax came to $4.80. What was the

snow_lady [41]

Answer:

Price of CD player = $96

Step-by-step explanation:

Given:

Sales tax = 5%

Amount of sales tax = $4.80

Find:

Price of CD player

Computation:

Price of CD player = Amount of sales tax / Sales tax

Price of CD player = 4.8 / 5%

Price of CD player = $96

6 0

2 years ago

MATH PLEASE HELP 20 POINTS!

Igoryamba

1. d
x-intercept (y=0) is -4
y-intercept (x=0) is 8

2. d
x-intercept (y=0) is 16
y-intercept (x=0) is 20

3. b
y=1/6x+4
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6y=x+24
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8 0

3 years ago

Read 2 more answers

I need help on 3 15 11 then explain pleases

zlopas [31]

Number 15 is 80 i dont know about the others...sorry

4 0

3 years ago

Solve this system of linear equations. separate the x- and y- values with a coma. -12x=-75-11y

ycow [4]

Solve the following system:
{-12 x = -11 y - 75 | (equation 1)
{-5 x = -11 y - 89 | (equation 2)
Express the system in standard form:
{-(12 x) + 11 y = -75 | (equation 1)
{-(5 x) + 11 y = -89 | (equation 2)
Subtract 5/12 × (equation 1) from equation 2:
{-(12 x) + 11 y = -75 | (equation 1)
{0 x+(77 y)/12 = (-231)/4 | (equation 2)
Multiply equation 2 by 12/77:
{-(12 x) + 11 y = -75 | (equation 1)
{0 x+y = -9 | (equation 2)
Subtract 11 × (equation 2) from equation 1:
{-(12 x)+0 y = 24 | (equation 1)
{0 x+y = -9 | (equation 2)

Divide equation 1 by -12:
{x+0 y = -2 | (equation 1)
{0 x+y = -9 | (equation 2)
Collect results:
Answer: {x = -2 {y = -9

please note that the parentheses "{" should span over both equations but the editor doesn't allow that so I should it on both line, See attached example.

4 0

3 years ago