# math: and i really need help

posted by
**pinkpolkadots7**
.

3x(a-5)=6 What is the value of a ?

3x(a-5)=6

is x multiplication or variable

multiplication

Multiplication=*

Division=/

3x(a-5)=6

3*(a-5)=6

(3*a)+(3*5)=6

3a+15-15=6-15

3a=-9

3a/3=-9/3

a=-3

I hope this helps. I am not 100% sure this is right.

Or it can be expressed as:

3 x (a-5) = 6

(3 * a ) - (3 x 5) = 6

3a - 15 = 6

3a = 15 + 6 = 21.

a = 21 / 3 = 7

To verify the answer:

3 x (7-5) = 6

3 x 2 = 6.

3 x (a-5)=6

(a-5) = 6/3 = 2

a = 2 + 5 = 7

I don't understand that......can you explain?

3 x (7-5) =6

7-5) =6/3 =2

7 = 2+5 = 7

3x(a-5)=6 If multiplication as you state, then,

3*(a-5)=6

Multiply by 3 on the left side to clear the parentheses.

3a-15=6

Then move the -15 to the other side, changing the sign in the process.

3a = 6+15.

Combine terms on the right.

3a = 21

Divide both sides by 3

3a/3 = 21/3

a = 7. Now check the answer of 7 by putting it into the orginal equation.

3*(a-5)=6

3*(7-5)=6

3*(2)=6

6=6

The answer of a = 7 checks.

oops, I did not change the negitive to positive. That's for correcting me.

i need help on order of operations

Do all operations inside the parentheses first.

Next, do any work with exponents or radicals.

Do all multiplication and addition from left to right.

Finally do all addition and subtraction from left to right