Question 76887This question is from textbook Prealgebra and Introductory Algebra
: The perimeter of a triangle is 85 inches. The sides are: 2x, 2x+5, and X squared + 3 Find the legths of the sides.
I though of putting them all together and then factoring, but it wasn't working out. If someone could help me I would really appreciate it.
Thank you very much for your time.This question is from textbook Prealgebra and Introductory Algebra
In order to factor , first we need to ask ourselves: What two numbers multiply to -77 and add to 4? Lets find out by listing all of the possible factors of -77
-1,-7,-11,-77,List the negative factors as well. This will allow us to find all possible combinations
These factors pair up to multiply to -77.
Now which of these pairs add to 4? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 4
We can see from the table that -7 and 11 add to 4.So the two numbers that multiply to -77 and add to 4 are: -7 and 11
Now we substitute these numbers into a and b of the general equation of a product of linear factors which is:
substitute a=-7 and b=11
So the equation becomes:
Notice that if we foil (x-7)(x+11) we get the quadratic again
So the quadratic factors to
Now set each term equal to zero
This answer doesn't make any sense (a negative length doesn't work)
So our answer is 7