Question

WILL MARK AS BRAINLIEST FOR THESE QUESTIONS.

Answer 1

1.

Let the sandwich be represented by = x

Let the drink be represented by = y

As given, Joe charges $10.00 for two sandwiches and one drink, so equation becomes 2x+y=10    ....(i)

He charges $6.50 for one sandwich and one drink, so equation becomes x+y=6.50  ....(ii)

Subtracting (ii) from (i) we get

x=3.50

And as x+y=6.50

y=6.50-3.50=3.00

Hence, cost of a sandwich is $3.50 and a drink is $3.00

2.

the question is incomplete. coordinates are missing

3.

Let x represent the number of performances

cost = 8000+300x

revenue = 700x

To break even, the cost must be equal to the revenue.

$8000+300x=700x$

$400x=8000$

so x=20

Hence, 20 performances are needed to break even.

4.

Let us take x for 20% material, y for 50% material

$\frac{20x+50y}{200}=30$

$20x+50y=6000$    ......... (1)

Accounting for volumes to use, x+y=200 or x=200-y ................ (2)

Putting the value of x in (1)

$20(200-y)+50y=6000$

$4000-20y+50y=6000$

$4000+30y=6000$

$30y=2000$

y=66.67

x=200-y = 200-66.67 =133.33

Hence, 133.33 ml of 20% acetic acid and 66.67% of 50% acetic acid is needed.