To solve this, you want to set each of the parentheses equal to 0 and then solve for the variable. a-9=0 To solve for a, add 9 to each side, making a=9. a+9=0 To solve for a here, subtract 9 from each side, making a=-9. The final answer is a=-9,9

(a-9)(a+9)=0 (answer)

To solve this, you want to set each of the parentheses equal to 0 and then solve for the variable. a-9=0 To solve for a, add 9 to each side, making a=9. a+9=0 To solve for a here, subtract 9 from each side, making a=-9. The final answer is a=-9,9

You first want to look at the values that make up the expression, 6y and 15. Obviously, you can't take a y out, because y is only in one of the values. Now, you compare 6 and 15. These have a common factor of 3, so you need to divide each by 3. You get a final answer of 3(2y+5)

Looking at 8x and 8y, you can tell that both have a common factor of 8. If you factor 8 out of both, you will reach a final answer of 8(x+y)

Both 7a and 7b can have a 7 factored out of them, so you would get a final answer of 7(a-b)

The greatest common factor of 2a and 10b is 2, so if you divide each of these by 2, you get 2(a+5b)