How do you evaluate the following expression using decimals?: # 4.136 - 8.2612 + 77/64 + 205/128#

1 Answer
Apr 27, 2016

#4.136-8.2612+77/64+205/128=-1.3205125#

Explanation:

Here #77/64# and #205/128# have only #2# as prime factors for denominators. In fact they are #2^6# and #2^7# and hence they can be converted into decimal form by multiplying numerator and denominator by #5^6=15625# and #5^7=78125#.

Hence #77/64=1.203125# and #205/128=1.6015625#.

Hence #4.136-8.2612+1.203125+1.6015625=-1.3205125#