Error is between steps 4 and 5. It should say:
Step 4: -9x < 27
Now divide by -9
Step 5: x > -3
Note that the inequality changes direction.
When you mean multiply or divide an inequality by a negative number, the inequality changes direction.
For example:
4 < 5
Multiply by -1:
-4 > -5
Another example:
-5 < 0
5 > 0
Answer:
600
Step-by-step explanation:
.7x = 420
x = 420/0.7
x = 600
2n + 1
the number before n is the difference (what it goes up in), and the second is the ‘zeroth’ term: you take away the 2 you got from the first value, 3, and get 1 :)
Answer:
number of adults tickets sold = x = 90
number of teachers tickets = y = 45
number of students tickets = z = 145
Step-by-step explanation:
Cost of tickets
Adults = $6
Teachers = $4
Students = $2
Total tickets sold = 280
Total revenue = $1010
Let
x = number of adults tickets
y = number of teachers tickets
z = number of students tickets
x + y + z = 280
6x + 4y + 2z = 1010
If the number of adult tickets sold was twice the number of teacher tickets
x = 2y
Substitute x=2y into the equations
x + y + z = 280
6x + 4y + 2z = 1010
2y + y + z = 280
6(2y) + 4y + 2z = 1010
3y + z = 280
12y + 4y + 2z = 1010
3y + z = 280 (1)
16y + 2z = 1010 (2)
Multiply (1) by 2
6y + 2z = 560 (3)
16y + 2z = 1010
Subtract (3) from (2)
16y - 6y = 1010 - 560
10y = 450
Divide both sides by 10
y = 450/10
= 45
y = 45
Substitute y=45 into (1)
3y + z = 280
3(45) + z = 280
135 + z = 280
z = 280 - 135
= 145
z = 145
Substitute the values of y and z into
x + y + z = 280
x + 45 + 145 = 280
x + 190 = 280
x = 280 - 190
= 90
x = 90
Therefore,
number of adults tickets sold = x = 90
number of teachers tickets = y = 45
number of students tickets = z = 145
