Four chairs and two tables cost £218. Six chairs and seven tables cost £587.

Find the total cost of buying twenty chairs and five tables.

x = cost of a chair = £22

y = cost of a table = £65

£765

Step-by-step explanation:

Let

x = cost of a chair

y = cost of a table

4x + 2y = 218 (1)

6x + 7y = 587 (2)

Multiply (1) by 6 and (2) by 4

24x + 12y = 1,308 (3)

24x + 28y = 2,348 (4)

Subtract (3) from (4) to eliminate x

28y - 12y = 2,348 - 1,308

16y = 1,040

y = 1,040/16

y = 65

Substitute y = 65 into (1)

4x + 2y = 218 (1)

4x + 2(65) = 218

4x + 130 = 218

4x = 218 - 130

4x = 88

x = 88/4

x = 22

x = cost of a chair = £22

y = cost of a table = £65

Find the total cost of buying twenty chairs and five tables

20x + 5y

Substitute the values of x and y

20x + 5y

= 20(22) + 5(65)

= 440 + 325

= £765

use an equation of ratios to determine the amount of gas needed to fill the tank.

    0.2             0.8

  =    

288.75             x

                                                              231 gal

so, 0.2x = (0.8)(288.75 gal), and x = = 1155 gal.

                                                                0.2

it would take 1155 gal. to fill the tank.

the cost would be

1155 gal         $3

* = $3465   (answer)

      1           1 gal

hope this you

1 number

if we use a graphing calculator, there is only one such number that satisfies the conclusion of the mean value theorem, that is, a number such that

where the right-hand side is the average rate of change of f on the interval [0.5,0.75], which is the slope of the secant line.

in the attached graph, the black line is the secant line which has its slope as the average rate of change of f on [0.5,0.75], while the orange line is the only tangent line to the graph of f in the interval that satisfies the mvt conclusion.