What is the answer to this Math Problem?

Question

The Question is:
5z > -45
The Choices are:
A) z > -225
B) z > -9
C) z < 9
D) z < -9
If anyone can explain to me how to do this, it would be appreciated.

Answer 1

do it as 5z = - 45. The answer to that is =45 / 5, or -9.

If 5z is greater than -45, then Z has to be greater than negative 9, so the correct answer is B.

Answer 2

Ok.. this can be a bit tricky.. with the > operation...

with inequalities, if you add, subtract, multiply or divide by a POSITIVE number.. then you are ok with the same symbol of < or >...

However, if you multiply or divide by a negative number.. then you must REVERSE the direction of the arrow.. so < becomes > or > becomes <.... you can work this through using small, easily multiplied numbers like 1,2, -1, -2.. etc..

for your problem.. it is straight forward... divide both sides by 5

5z > -45
divide by 5 ==> z > -9

if you had divided by -5 (not needed to solve the problem.. but a common mistake):

5z > -45
divide by -5 ==> -z < 9
multiply by -1 ==> z > -9

ok.. that should help.. I hope

Answer 3

The answer is B.

You kinda have to do this problem backwards to get the answer.

ok... First you need to divide 5 by both sides (the opposite of multiplying is dividing) 5/5z > -45/5. The 5/5 cancels out so you are left with z > -45/5. Now, all you need to do is divide -45 by 5 to get your answer which is z > -9 (B).

Answer 4

if 5 (same size)bananas weigh 45 grams, then one banana weighs 9 grams

in the same way, if 5 bananas weigh more than 45 grams, one banana weighs more than 9 grams

You can do the same to the inequality given:

5z>-45 means that z > -45/5

It may be this is the problem?
What is -45 divided by 5?
If you multiply 2 numbers together to get a negative number, one must be positive, the other negative, so -45= -5*9 or 5*-9 for example.

In this case its 5*-9, so -45/5=-9

SO THE ANSWER IS z>-9

Answer 5

You treat inequalities the same way as equations except that when you multiply or divide by a negative number, you switch a greater than to a less than and vice versa. For this one, just divide by 5 to get z>-9.

Answer 6

> means greater than
5z means 5 x Z
5 x Z must be greater than -45
5 x 9 = 45
Z must be a positive number in order to be greater than a negative number therfore the answer is C
Z can be less than the number 9 as long as it is a positive number.

Answer 7

It's "B". Remember that < -9 .....the numbers go more negative. So they go -10, -11, -12, etc. Any of those numbers just give you a bigger negative number. So you have to go the other way from -9. That makes it "B"

Answer 8

b.

Look, divide both sides by 5; you get z on the left, and -9 on the right.

Since you're not multiplying by a negative number, you don't have to flip the inequality.

Simple enough?

Answer 9

its B. divide 5 from both sides
5z/5=z
-45/5= -9
z> -9

Answer 10

B. Divide each side by 5, and there you have it. (Keep in mind: if you would divide by a negative number, flip the inequality sign, ie. > to <.)
Feel free to email me if you have any other math questions :)