All ACT Math Resources
Example Questions
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.
Example Question #5 : How To Use Scientific Notation
Convert from scientific to decimal notation:
In this case the exponent is positive hence you have to move the decimal point 4 places to the right from where it is in the problem giving us
Example Question #1 : How To Use Scientific Notation
Convert from decimal to scientific notation:
In this case you have to move the decimal point 6 places to the right. When you move the decimal point to the right the exponent becomes negative. Similarly when you move the decimal point to the left the exponent is positive. Also, to the left of the decimal place there can be only one digit.