Question

Four times the square of a certain number increased by 6 times the number equals 108. Find the number

Answer 1

-6 and 4.5
So to do this you’ll make an equation x will represent the number so 4x^2+6x=108 so we want the equation to equal 0 so we can solve it to do that you have to subtract 108 from both sides so it ends up being 4x^2+6x-108=0 we want to isolate the x onto one side and division property allows us to divide both sides by 2 the reason it’s two is because 2 is the biggest divisible number that every number in the equation is divisible by so once you divide every number by two you get 2x^2+3x-54=0 now you have to factor cause but since you only have 3x and nothing else to factor with you have to write 3x as a difference so you could do 2x^2+12x-9x-54=0 so you are complicating the problem so you can factor out 2x from the expression so 2x(x+6)- 9(x+6)=0 the 54 got factored because it’s divisible by 9 that 6 is in replace of the 54 cause if you solved it 9x6 is still 54 next factor out x+6 so (x+6) x (2x-9) =0 so one of the two have to equal 0 so right the equations separately x+6=0 minus 6 from both sides and you’ll get x to equal -6 and 2x-9=0 add 9 to both sides and you’ll get 2x=9 divide both sides by 9 and you’ll get x to equal 4.5 when you plug 4.5 and -6 for x the equation works out