Directions: Simplify the following monomials (if possible). 6.) -10a²b² - a²b²
7.) -8mn + 9mn
9.) -25xy² - 25xy²
10.) -50ac²d + ac²d
11.) 3y + 9z + 4y - 3z

-ANYONE PLEASE HELP ME I REALLY NEED THE ANSWER RIGHT NOW BECAUSE I HAVE TO PASS THIS LATER I HOPE Y'ALL CAN HELP ME:(
I'LL MARK YOU AS THE BRAINLIEST!​

6) it’s -11a^2b^(because they have the same letters plus both of them have squares and if there isn’t any number in the on the other side it means that it is 1)
7)1mn(subtract and then put the sign of the bigger number)
9)-50xy^2(addition)
10)-49ac^d(subtract and put the sign of the bigger number)
11) 7y + 6z(arrange them first and then add and subtract.)
(Hope this helps)

Horizontal change or the change of x