ACT PREP

PROBLEM #19

WHEN X=(1/2)

OPTIONS...

• A) -20
• B) -2
• C) -1/2
• D) 1
• E) 1/2

FIRST: EQUIP X

REPLACE AN X WITH 1/2

• 4x-3 becomes ((1/2)4)-3
• -Or one half of 4, minus 3
• The denominator becomes 1/2
• So.. ((1/2)4)-3/(1/2)
• No more X

REMEMBER "PEMDAS"

PARENTHESES GO FIRST

• ((1/2)4) = 2
• 2-3/[1/2]
• So, we're left with:
• -1 over [1/2]

NOW WHAT?

1 is double of (1/2)
So the answer is 2.
Remember that 1 was a negative as well.
The negative must come along with the one so...
The full answer is:
😛 B) -2 😛

ANOTHER WAY TO ANSWER IT

BACK TO REPLACING X

• We had (1/2)4)-3/(1/2)
• Multiply both top and bottom
• to get rid of the fractions.
• 2*(1/2)4)-3/(1/2)*2)
• 2*(1/2)4)-3

CONTINUING..

• 2*(1/2)4)-3
• 2*(2-3)
• 2*(-1)
• = -2
• The answer is still B) -2

Any Questions?
Any Comments?