Studying trigonometry

[brocode]

can you solve this?

∭E1dV

E ={(x,y,z)|0≤x≤1,0≤y≤1−x,0≤z≤1−x−y}.

while i wrote out the E = in a bit of a complex format that you may not have seen that format before, this is a very simple integral and triple integrals are also nothing special, you should really just google up how to do basic integrals as this question is very low level and i assume anyone who googles triple integrals should be able to solve this question in max 30 minutes but anyone who actually learned this stuff should be able to do it in like 1 or 2 minutes and that's just the time it takes to actually write it with a pencil

i know how to do integrals and double differentiation and differential equations too but not triple integrals.
but yes, after u posted this, i did google it and came across such a question in uni of notre dame's website.

i've been reading up on it