Evan digs into his pocket to see how much pizza he can afford. He has $3.00, exactly enough for two slices. But it is all in dimes and nickels! Counting carefully, Evan discovers that he has twice as many dimes as nickels.

Black Bart and the Sheriff are having a gunfight at high noon. They stand back to back, and start walking away from each other: Bart at 4 feet per second, the Sheriff at 6 feet per second. When they turn around to shoot, they find that they are 55 feet away from each other.

Figure 1

Mrs. Verbatim the English teacher always assigns 5 short stories (2,000 words each) for every novel (60,000 words each) that she assigns. This year she has decided to assign a total of 350,000 words of reading to her students. How many books and how many short stories should she select?

Solve by graphing. Answers may be approximate. (But use the graph paper and get as close as you can.)

y = x 2 − 3 y = x 2 − 3 size 12{y=x rSup { size 8{2} } - 3} {}

y = − ∣ x ∣ + 2 y = − ∣ x ∣ + 2 size 12{y= - lline x rline +2} {}

Solve, using substitution.

3x + y = − 2 3x + y = − 2 size 12{3x+y= - 2} {}

6x − 2y = 12 6x − 2y = 12 size 12{6x - 2y="12"} {}

Solve, using elimination.

2x + 3y = − 11 2x + 3y = − 11 size 12{2x+3y= - "11"} {}

3x − 6y = 4 3x − 6y = 4 size 12{3x - 6y=4 { size 8{1} } wideslash { size 8{2} } } {}

Solve any way you like.

2x = 6y + 12 2x = 6y + 12 size 12{2x=6y+"12"} {}

x − 9 = 3y x − 9 = 3y size 12{x - 9=3y} {}

Solve any way you like.

2y + 3x = 20 2y + 3x = 20 size 12{2y+3x="20"} {}

y + x = 6 y + x = 6 size 12{ { size 8{1} } wideslash { size 8{2} } y+x=6} {}

ax + by = e ax + by = e size 12{ ital "ax"+ ital "by"=e} {}

cx + dy = f cx + dy = f size 12{ ital "cx"+ ital "dy"=f} {}

3x + 4y = 7 3x + 4y = 7 size 12{3x+4y=7} {}

2x + 3y = 11 2x + 3y = 11 size 12{2x+3y="11"} {}