Answer:
23/12 or 1 and 11/12
Step-by-step explanation:
Your first step is that you need to gain a common denomitor. In this scenario, this is 12. To get this, you can either go through the given factors such as 3 having the factors of 6, 9, and 12 and 4 having the factors of 8, and 12.
Another method is the multiply the two given denominators together, but there are certain instances where you shouldn't do that.
Now that you have a common denominator, you need to change the numerators to accomadate the denominators. For 3 to turn into 12, you need to multiply it by 4, thus you have to do the same to the numerator. For 4 to turn into 12, you need to multiply it by 3. This will give you these two new fractions:
8/12 + 15/12
Add the numerators to get 23/12 and then simplify the two numbers to get the mixed number of 1 and 11/12.
Hope this helps!
A. You can factor it to those terms
Answer:
Step-by-step explanation:

Subtract 4 times the first equation from the second:
(-7y +16x -80) -4(-9y +4x -20) = (0) -4(0)
29y = 0 . . . . . simplify
y = 0 . . . . . . . .divide by 29
4x -20 = 0 . . . . substitute 0 for y in the first equation
x -5 = 0 . . . . . .divide by 4
x = 5 . . . . . . . . add 5
The solution to this system is (x, y) = (5, 0).