Ximena and Darius left a 20% tip after having dinner at a restaurant. The amount of the tip was $5. Ximena’s dinner cost $15. Which equation can you use to find x, the cost of Darius’s dinner?

0.2 (15+x) = 5

Step-by-step explanation:

Let 'x' represent  cost of Darius’s dinner

Ximena’s dinner cost $15, that will be added to cost of Darius's lunch i.e 'x'.  They left a 20% tip on the TOTAL cost of both their lunches that would be equal $5.  So, the equation is 5=0.2(x+15). 20% (0.2) of the sum of Ximena and Darius lunches i.e 5 dollars.

Equation : 0.2 (15+x) = 5

(0.2) (15) + 0.2x = 5

             3 + 0.2x = 5

                   0.2x = 2

                         x = 2/0.20

                         x = 10

Darius’s dinner  cost $10

Verification :  

15+10=25

25 x 0.20 = 5

34.5 cm

step-by-step explanation:

generally for a circular segment of angle, θ° and radius r

arc length

= (θ/360) x circumference

= (θ/360) x 2πr

in our case, θ = 60°, π=3.142 and r = 33 cm

substitute into above formula

arc length

= (60/360) x 2(3.142)( 33) = 34.5 cm