Mary H. answered • 02/21/18
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The area is length * width, you know that, so plug in the length and the width.
A = (x+ 5) (2x - 7) This is now a problem multiplying two binomials together. You are probably learning the FOIL method first.
Let's do a similar problem, then you can try your homework problem on your own.
A = (x+3) (4x- 5)
First Outer Inner Last
(x) (4x) (3) (-5x) (3) (4x) (3) (-5)
4x2 -15x + 12 x -15 Combine like terms
A = 4x2 -3x -15
Do the same with your problem. Keep working! If you still have a problem, let me know.
You can do it!
Mary
Lily M.
Actually you did it wrong the correct answer for the example problem you gave would be 4x^2 +7x -15 You accidently multiplied the 3 by the -5x twice you should have done it once and then x times -5x for the second time You also added an x to the 5 when you multiplied the first time by 3, you shouldn't have done that. Right now kids are learning the distrubitive method first (x+3)(4x-5) So first you distribute the first term in the first group of parentheses to the first term in the second group of parentheses x times 4x which equals 4x squared 4x^2 Then you distribute the first term in the first group of parentheses to the second term in the second parentheses x times-5 which equals -5x (attach this to what you already have) 4x^2 -5x Then you distribute the second term in the first parentheses to the first term in the second parentheses 3 times 4x which equals 12x (attach this to what uou already have) 4x^2 -5x +12x Then you distribute the second term in the first parentheses to the second term in the second parentheses 3 times -5 which equals -15 (attach this to what you have already) 4x^2 -5x +12x -15 Next you combine like terms (Like terms are numbers with the same variable and exponent, if it dosent have an exponent or variable for example 6 then it would be like terms with another term without a variable and exponent for example 3) 4x^2 -5x +12x -15 So your like terms in this expression are -5x and (positive) 12x They are like because they have the same variable and exponent, the variable is x and the exponent is 1. (When there isnt anexponent on a term that just means the exponent is one and it dosent really matter or need to be included) So when you combine -5x +12x you just subtract 5 from 12 and attach the exponent to the end 12-5=7 Attach the x 7x So now for your final answer you get 4x^2 +7x -1510/08/20