All ACT Math Resources
Example Questions
Example Question #4 : How To Find A Rational Number From An Exponent
Converting exponents to rational numbers often allows for faster simplification of those numbers.
Which of the following is incorrect? Convert exponents to rational numbers.
To identify which answer is incorrect we need to do each of the conversions.
First lets look at
.
Therefore this conversion is true.
Next lets look at . For this particular one we can recognize that anything raised to a zero power is just one therefore this conversion is true.
From here lets look at
Thus
. Therefore this is an incorrect conversion and thus our answer.
Example Question #6 : Exponents And Rational Numbers
Sometimes, seeing rational numbers makes it easier to understand an equation.
Convert the following into a rational number or numbers:
The rule for converting exponents to rational numbers is: .
Even with this, it is easier to work the problem as far as we can with exponents, then switch to rational expression when we run out of room:
At last, we convert, and obtain .
Thus,
.
Example Question #171 : Exponents
What is the sum of the solutions of the equation x2-2x-8=0?
-6
-10
-2
6
2
2
The equation factors to (x-4)(x+2)=0, indicating that the roots are x=-2,4. The sum of these two roots is 2.
Example Question #1 : How To Use Scientific Notation
What is the number 350,000,000 in scientific notation?
3.5 x 105
3.5 x 106
3.5 x 109
3.5 x 107
3.5 x 108
3.5 x 108
350,000,000 = 3.5 x 108 (exponent is equal to the number of decimal points shifted)
Example Question #872 : Algebra
Given the equation 2xy + 4x² - y = 2x, if x = 2, what does y equal?
0
-4
4
2
-4
We plug in the value given for x and solve for y.
2xy + 4x² - y = 2x
2(2)y + 4(2)² - y = 2(2)
4y + 4(4) - y = 4
4y - y + 16 = 4
3y = -12
y = -4
Example Question #2 : How To Use Scientific Notation
How do you express 657,800 in scientific notation?
6.578 × 104
65.78 × 106
6.578 × 103
65.78 × 104
65.78 × 103
65.78 × 104
657800 = 6.578 × 105
OR
657800 = 65.78 × 104
Exponent on 10 is the number of decimal points over the number has shifted.
Example Question #5 : Other Exponents
2 × 100 + 3 × 102 + 4 × 104 = ?
40,320
400,032
40,302
4,032
432
40,302
2 × 100 + 3 × 102 + 4 × 104 =
2 + 300 + 40,000 = 40,302
Example Question #1 : How To Use Scientific Notation
Give this number in scientific notation:
There are six zeros and two more number places, for a total of eight, so 125,000,000 is equivalent to .
Example Question #4 : How To Use Scientific Notation
Simplify the following expression:
Example Question #1 : Other Exponents
What is the number in scientific notation?
The exponent is equal to the number of decimal points shifted.