1. ## quick simplifying question

i have a quick question with simplifying a variable expression can someone tell me what one is correct? heres the problem 8-12x+20 is simplified to what A)28-12x or B)-12x+28?

2. Both the expressions A) and B) are equal.

3. wow, yea im stupid i checked it in the calculator before i posted, but i must of put it in wrong bcuz now it comes out correct

4. im not going to open up a new thread for this but can anyone figure this out?

find three consecutive integers such that the sum of the first two is 18 more than the third

5. Let the 3 consecutive integers be $\displaystyle a-1,\ a,\ a+1$

$\displaystyle (a-1)+a=18+(a+1)$

$\displaystyle 2a-1=19+a$

$\displaystyle a=20$

So the 3 integers are 19, 20 and 21.

6. what about find the measure of the three angles of a triangle if the second angle is twice the first angle and the third angle is 20 more than the first angle?

7. First angle = x
Second angle = 2x
Third angle = x + 20

The sum of the three angles in a triangle is 180:
x + 2x + x + 20 = 180

Can you take it from here?

01

8. yes i can take it from there, idk why u have such a hard time setting these up, 2 more if u dont mind

a 31 inch pipe is cut into two pieces. three times the larger piece is equal to nine more than three times the smaller piece.find the lenth of the smaller peice

^that one i dont even know how to set up

heres the last one
if you reveived a 58 and a 78 on the first two math test, what grade would you need on the next test to have a 70 average

^now that one i got the answer to wich is 74 but i had to do it the long way because i have such a hard time trying to set up these problems

9. Originally Posted by wonderd
yes i can take it from there, idk why u have such a hard time setting these up, 2 more if u dont mind

a 31 inch pipe is cut into two pieces. three times the larger piece is equal to nine more than three times the smaller piece.find the lenth of the smaller peice

^that one i dont even know how to set up
Take the first part of the problem: "a 31 inch pipe is cut into two pieces." So there are two pieces with lengths x and y. Together their length must equal 31 inches. "Together" means addition, so
$\displaystyle x + y = 31$

Now take the second part of the problem: "three times the larger piece is equal to nine more than three times the smaller piece."
Again, we have the lengths of the two pieces of pipe, x and y. It doesn't matter which is larger; let's say that x is. So
"three times the larger piece..." means 3x,
"is equal to..." means =,
"nine more than three times the smaller piece." means 3y + 9.
Therefore the 2nd equation is
$\displaystyle 3x = 3y + 9$.

You have two equations and two unknowns.
$\displaystyle x + y = 31$
$\displaystyle 3x = 3y + 9$
Can you take it from there?

heres the last one
if you reveived a 58 and a 78 on the first two math test, what grade would you need on the next test to have a 70 average
To find the average of a bunch of numbers, add the numbers up and divide by the number of numbers there are. How many test grades are there? Three: 58, 78, and an unknown number, which we'll call x. Find it's average:
$\displaystyle \frac{58 + 78 + x}{3} = 70$
That's the equation. Take it from there!

01

10. You have two equations and two unknowns.

Can you take it from there?

i havent gotten that far in math yet, idk how to find two unknows, and its asking for one number not 2