-3x = 21
Divide -3 from both sides and you get x = -7
1/3x = 6
Divide 1/3 from both sides and you get x = 18
-1/2x = -7
Divide -1/2 from both sides and you get x = 14 (you get a positive answer from 2 negatives)
Dividing 1/3 is just multiplying by 3, and dividing -1/2 is just multiplying by -2
So the sum of 4 times a number (4 times x or 4x) and 7 (+7) is (=) 19 (19)
4x+7=19
subtract 7 from both sdies
4x=12
divide by 4
x=3
the number is 3
Answer:
When x = 1 and z = 4, 
Step-by-step explanation:
The variation described in the problem can be written using a constant of proportionality "b" as:

The other piece of information is that when x = 5 and z = 1, then y gives 25/9. So we use this info to find the constant "b":

Knowing this constant, we can find the value of y when x=1 and z=4 as:

Answer:
3x+6
Step-by-step explanation:
(x+2)3
3(x)+3(2)
3x+6