Answer:
12x-7y+3z
Step-by-step explanation:
H(10) is the altitude of a hot air balloon overtime after 10 minutes. In order to find h(10)'s value, you just have to substitute 10 as t in the equation. h(10) and h(t) represents the value of y in a linear equation. So pretty much: h(10)= 210 - 15(10). If calculated correctly, h(10)=60.