Evaluate <span class="katex-r" data-latex="displaystyle i∫_S x^2 d y d z+y^2 d z d x+z^2 d x d y"></span>, whe <span class="katex-r" data-latex="displaystyle S"></span> is the boundy of the teaheon def∈ed by <span class="katex-r" data-latex="displaystyle x+y+z ≤ 1"></span> and <span class="katex-r" data-latex="displaystyle x, y, z ≥ 0"></span>, outwd.