Watch Video on Coin Word Problems – Algebra Help
Tuesday, March 2nd, 2010
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/coinproblems.php Students learn to solve “value” word problems, such as the following. Martin has a total of 19 nickels and dimes worth $1.65. How many of each type of coin does he have? Note that this problem requires a chart to organize the information. The chart is based on the total value formula, which states that the number of coins times the value of each coin = the total value. The chart is then used to set up the equation.
Duration : 0:4:50
Access full lesson containing this video at: http://www.yourteacher.com/algebra2/multiplyingcomplexnumbers.php Students learn to add, subtract, multiply, and divide complex numbers that contain radicals. For example, to divide (3 + 5i root 11) / (6 + 2i root 11), the first step is to multiply both the numerator and denominator of the fraction by the conjugate of the denominator, which is (6 — 2i root 11), then FOIL in both the numerator and denominator, and combine like terms.
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/algebrawordproblems.php Students learn to solve “number” word problems, such as the following. One number is four times as large as another. The sum of the numbers is 45. Find the numbers. Since the first sentence states that one number is 4 times as large as another, the numbers can be represented as x and 4x. Since the second sentence states that the sum of the numbers is 45, the equation can be set up as x + 4x = 45.
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/simplifyingradicals.php Students learn to simplify a square root by setting up a factor tree for the number inside the radical. If a factor pairs up in the factor tree, then it comes out of the radical. If a factor does not pair up, then it stays inside. Students also learn to simplify a cube root by setting up a factor tree for the number inside the radical. If a factor is part of a group of three factors that are the same, then it comes out of the radical. If a factor is not part of a group of three factors that are the same, then it stays inside.
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/completingthesquare.php Students learn to solve quadratic equations by completing the square. For example, to solve the equation s^2 – 6s + 5 = 0, the first step is put the constant term on the opposite side of the equation as the terms that contain the variables, by subtracting 5 from both sides, to get s^2 – 6s ___ = – 5 ___. Next, the number that goes in each space comes from half the coefficient of the middle term squared, which in this case is half of -6, or -3, squared, which is +9. So a +9 goes in each space, to get s^2 – 6s + 9 = – 5 + 9. The trinomial on the left side of the equation then factors as (s – 3)(s – 3), or (s – 3)^2, and the right side of the equation simplifies to 4, so the problem now reads (s – 3)^2 = 4. Finally, take the square root of both sides to get s – 3 = plus or minus 4, so s – 3 = 4, or s – 3 = -4, and solving each equation from here, s = 7 or -1.