Work the information to set inequalities that represent each condition or restriction.
2) Name the
variables.
c: number of color copies
b: number of black-and-white copies
3)
Model each restriction:
i) <span>It
takes 3 minutes to print a color copy and 1 minute to print a
black-and-white copy.
</span><span>
</span><span>
3c + b</span><span>
</span><span>
</span><span>ii) He needs to print
at least 6 copies ⇒
c + b ≥ 6</span><span>
</span><span>
</span><span>iv) And must have
the copies completed in
no more than 12 minutes ⇒</span>
3c + b ≤ 12<span />
4) Additional restrictions are
c ≥ 0, and
b ≥ 0 (i.e.
only positive values for the number of each kind of copies are acceptable)
5) This is how you
graph that:
i) 3c + b ≤ 12: draw the line 3c + b = 12 and shade the region up and to the right of the line.
ii) c + b ≥ 6: draw the line c + b = 6 and shade the region down and to the left of the line.
iii) since c ≥ 0 and b ≥ 0, the region is in the
first quadrant.
iv) The final region is the
intersection of the above mentioned shaded regions.v) You can see such graph in the attached figure.
Answer:
an average 7th grader owns 3 pairs of sneakers
Answer: 90 and 110
Step-by-step explanation:
Answer: the bill for a hamburger is $0.7
the bill for a salad is $1.5
Step-by-step explanation:
Let x represent the bill for a hamburger.
Let y represent the bill for a salad.
The bill for five hamburgers and four salads is $9.50. This means that
5x + 4y = 9.5- - - - - - - - - - - - - - 1
The bill for four hamburgers and five salads is $10.30. This means that
4x + 5y = 10.3 - - - - - - - - - - - - - -2
Multiplying equation 1 by 4 and equation 2 by 5, it becomes
20x + 16y = 38
20x + 25y = 51.5
Subtracting, it becomes
- 9y = - 13.5
y = - 13.5/ - 9
y = 1.5
Substituting y = 1.5 into equation 1, it becomes
5x + 4(1.5) = 9.5
5x + 6 = 9.5
5x = 9.5 - 6 = 3.5
x = 3.5/5 = 0.7