Help! GHJ Café sells Medium and large coffees to locals in Downtown Dallas. If 7 medium cups and 10 large cups of coffee are sold, the café makes $68.75 in sales. If 10 medium and 15 large cups are sold, the total sales is $101.25. How much does a large cup of coffee sell for at GHJ Café?

Large cup cost $4.25

Step-by-step explanation:

Medium:  x

   Large:  y

Constraints:

  7x + 10y = 68.75

  10x + 15y = 101.25

Isolate y variable:

     (7x + 10y = 68.75) * -10    ===>    -70x - 100y =  -687.50

   (10x + 15y = 101.25) * 7       ===>     70x + 105y = 708.75

   add the two equations                                 5y = 21.25

   divide by 5                                                      y = 4.25

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it