Answer:
1/5
Step-by-step explanation:
I believe the answer is A
Solution
-6x - 3y = 9 Add 6x to both sides
-6x + 6x - 3y = 9 + 6x
-3y = 9 + 6x Or more conventionally
-3y = 6x + 9 Divide by - 3
y = 6x/-3 + 9/-3
y = - 2x - 3
You have to distribute!
6(x) = 6x and 6(-6)=-36
So now you have 6x-36=-3(-x+3)
Now do the same on the other side.
-3(-x)=3x -3(3)=-9
So now, 6x-36=3x-9
Combine the like terms:
Subtract 3x in both sides.
6x-3x=3x
Now: 3x-36=-9
Add 36 in both sides.
3x=27
Divide by 3 on both sides to get x alone.
3x/3= x 27/3=9
X=9
B. 16 cm
Square both 20 and 12
20x20=400
12x12=144
400-144=256
find the square root of 256
and the square root is 16
so b is 16 cm