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How do you solve x2-3x-28 equals 0?
You can use the quadratic formula for an equation of the form a*x^2 + b*x + c = 0. x = (-b +/- sqrt(b^2-4*a*c))/(2*a) In this case: a = 1 b = -3 c = -28 x = (3 +/- sqrt(9 - 4*(-28)))/2 x = (3 +/- sqrt(121))/2 x = (3 +/- 11)/2 x = 7 or -4 Another option is to attempt to simplify the equation into the form (x-a)(x-b) = 0. Sometimes you can do this by observation. For example: 28 = 4*7 7-4 = 3 Thus: (x-7)(x+4)=0 In this case, a and b are known as the "roots" of the equation, with a = 7 and b = -4.
What are factors in an expression?
Factors aremultiplicativeterms (i.e., they multiply into all the terms). The easiest way to see this is by example.Example 1:a(b+cd)a is a factor and (b+cd) is a factorExample 2:x2 - 9 = (x-3)(x+3)(x-3) is a factor and (x+3) is a factorHopefully you are beginning to notice you can always wrap parenthesis around a factor without altering the order of operations.Example 3:2a(b)(9n-x)+8This is a trick one, but you can factor out a 2:2a(b)(9n-x)+8 = (1)(2)a(b)(9n-x)+(4)(2) = (2)(ab(9n-x)+4)The factors are: 2 and (ab(9n-x)+4)Example 4:If that +8 wasn't on example 3, what would the factors be?2a(b)(9n-x)They would be:2, a, b, and (9n-x)
Which equation describes the line with a slope of 2 and contains the point (4-3)?
The equation of a line with slope m through a point (x0, y0) has equation: y - y0 = m(x - x0) Thus the equation of the line with slope 2 through the point (4, -3) has equation: y - (-3) = 2(x - 4) → y + 3 = 2x - 8 → y = 2x - 11
How do you write the equation of the line in standard form through 4 and 0 and 0 and 3?
In y=mx + b form, y = (-3/4)x - 3 - Found the slope (m) to be -3/4 - Substituted slope and a point into y = mx + b to find y-intercept (b). - b = - 3 , Substitute b and m into y=mx+b
In chest A there are three times as many coins as in chest b altogether there are 120 coins how many coins are there in chest B?
there are 30 coins in chest B...3/4 of the total are in A and 1/4 of the total are in B. So you divide 120 by 4 and get 30. So 30 x 3 = 90 = A, and 30 x 1 = 30 = B
