Calculate how much gasoline and money could be saved if the automobile's fuel efficiency were increased by 25%.

gasoline = 25 gallons per week
money = $2 per gallon ($50 total)

In the question it is already given the amount of actual gasoline and money consumed before the fuel efficiency gets increased by 25%
Gasoline consumption before the increase in fuel efficiency = 25 gallons per week
Gasoline saved after the increase in fuel efficiency = [25 * (25/100)] gallons per week
                                                                                             = 6.25 gallons per week
So every week 6.25 gallons of gasoline can be saved after increasing the efficiency of the automobile by 25%.
Then
The amount of money saved against the 6.25 gallons of gasoline saved = (6.25 * 2) dollars
                                                                                                                   = 12.50 dollars
The amount of money saved is $12.50 per week.

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer