footboy7517 footboy7517 28-09-2018 Mathematics contestada Use benchmarks to estimate each sum or difference. 4/5 + 8/9 a. about 1 1/2 b. about 1 3/4 c. about 1 8/9 d. about 2 Use benchmarks to estimate each sum or difference. 17/18 + 3/7 a. about 1/4 b. about 1/2 c. about 0 d. about 1