Answer:
45
Step-by-step explanation:
These work problems are always done in terms of fractions ie if both (Kevin & Eric) took 30mins to mow and Kevin took 1.5hrs (90mins) alone then we can make an equation like below
1/time took for both = 1/time took for Kevin + 1/time took for Eric
1/30 = 1/90+1/x ==> calling time took for Kevin x
solving the above 1/x = 1/30-1/90
1/x=2/90
x=45
Answer:176 psychology textbooks and 98 Biology textbooks were sold.
Step-by-step explanation:
Let x represent the number of psychology textbooks that were sold.
Let y represent the number of biology textbooks that were sold.
textbook store sold a combined total of 274 psychology and biology textbooks in a week. This means that
x + y = 274 - - - - - - - - - - -1
The number of psychology textbooks sold was 78 more than the number of biology textbooks sold. This means that
x = y + 78
Substituting x = y + 78 into equation 1, it becomes
y + 78 + y = 274
2y = 274 - 78
2y = 196
y = 98
x = y + 78 = 98 + 78
x = 176
Answer:
166,000
Step-by-step explanation:
1x166,000=166,000
Answer:
10
Step-by-step explanation:
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Do substitution
2(7-2y) = 5
14 - 4y = 5
-4y = -9, y = 9/4
2x + 9/4 = 5
8x + 9 = 20
8x = 11, x = 11/8
Final answer: x = 11/8, y = 9/4