12+ [0.4×0.75+(7.5+△)×3] ÷0.3=98,求△=?
问题描述:
12+ [0.4×0.75+(7.5+△)×3] ÷0.3=98,求△=?
答
12+[0.3+22.5+3Δ]÷0.3=98
12+76+10Δ=98
88+10Δ=98
10Δ=98-88
Δ=1