Roberto overtakes Juanita at the rate of (7.7 mi)/(11 h) = 0.7 mi/h. This is the difference in their speeds. The sum of their speeds is (7.7 mi)/1 h) = 7.7 mi/h.
Roberto walks at the rate (7.7 + 0.7)/2 = 4.2 mi/h.
Juanita walks at the rate 4.2 - 0.7 = 3.5 mi/h.
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In a "sum and diference" problem, one solution is half the total of the sum and difference. If we let R and J be the respective speeds of Roberto and Juanita, we have
R + J = total speed
R - J = difference speed
Adding these two equations, we have
2R = (total speed + difference speed)
R = (total speed + difference speed)2 . . . . . as computed above
Answer:
are there answer choices?
Step-by-step explanation:
4 times bbbbbbbbbbbbbbbbbbb
Step-by-step explanation:
25.2 + 800 - 427.43 x 2.4 ÷ 13
825.2 - 1025.832 ÷ 13
200.632 ÷ 13
= 15.44
Answer:
79 electrons
Step-by-step explanation:
If it has 79 protons it will have a total proton charge of 79 so tho make the charge zero we need to add (79) electrons .Mathematically (1*79)+(-1*79)=0
