甲数是8.45,乙数比甲数多3.02,丙数比乙数少1.24,求甲乙丙三数之和是多少?

问题描述:

甲数是8.45,乙数比甲数多3.02,丙数比乙数少1.24,求甲乙丙三数之和是多少?

8.45+(8.45+3.02)+(8.45+3.02-1.24)
=8.45+8.45+3.02+8.45+3.02-1.24
=8.45+8.45+8.45+3.02+3.02-1.24
=8.45×3+3.02×2-1.24
=25.35+6.04-1.24
=30.15