A
These are multiples of 3 so 3x where x is a natural number from 0 to 4. In set builder notation we get {3x | x c Z, 0<= x <= 4}
By c I mean the symbol for “is an element of” which looks like a drawn out rounded upper case E. By <= I mean less than or equal to
B
These are integers from -3 to 3. That is {x| x c Z, -4 < x < 4
C
Here we have letter from the English alphabet from m to p.
{x| x c letter of the English alphabet from m to p}
a.
b=cost per burrioto
t=cost per taco
b.
3 burritos and 4 tacos costs 11.33; 3b+4t=11.33
9 burritos and 4 tacos costs 22.07; 9b+4t=22.07
c. solve
3b+4t=11.33
9b+4t=22.07
mulitply irst equation by -1 and add to 2nd to cancel t's
-3b-4t=-11.33
<u>9b+4t=22.07 +</u>
6b+0t=10.74
6b=10.74
divide both sides by 6
b=1.79
subsitute back
3b+4t=11.33
3(1.79)+4t=11.33
5.37+4t=11.33
4t=5.96
divide both sides by 4
t=1.49
solution: 1 taco costs $1.49 and 1 burrito costs $1.79
For the first the correct answer is C
the second
the perimiter of the triangle is equal the sum of the sides
x +x-1+x-2= 12
3x = 12 +3
x= 15/3 = 5
