If a triangle's height is 4 inches less than two times it's base, and has an area of 120 square inches. What is the height of the triangle? I know it's 20 inches but i need to show how I found it, but the equation I used [120 = 1/2b(2b  4)] doesn't turn out right. Area of a triangle = (base x height)/2
"height is 4 inches less than two times its base" {usually whatever comes after the word than is what you let x equal} x = base 2x  4 = height x(2x  4)  = 120 2 2x2  4x = 240 {multiply both sides by 2 to clear fraction out} 2x2  4x  240 = 0 {subtract 240 from both sides} 2(x2  2x  120) = 0 {factor 2 out} 2(x + 10)(x  12) = 0 {factor into 2 binomials} x + 10 = 0 or x  12 = 0 {set each factor equal to 0} x = 10 or x = 12 {solve each equation for x} x cannot be negative x = 12 2x  4 = 20 inches {the height}  Algebra House
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