a weights m kg, b weight is 20 kg less than three times that of a. If their total weight is 100 kg. Find the weight of a

30kg

Step-by-step explanation:

what we know is that 3a - 20kg is b. and if a + 3a -20kg = 100kg, it becomes algebra .

So, we move it over to the sides:

4a = 120kg

(here i moved -20kg to the 100kg and did the reverse. I also added the a's)

which means a = 120kg divided by 4

a = 30kg

relating to or denoting a system of numbers and arithmetic based on the number ten, tenth parts, and powers of ten.

step-by-step explanation:

i get you, what you should do is think of the positive things that would come out of it. it will make yours parents proud and raise your grade. you should always try and if you can't focus tell the teacher.