How do you solve #2x ( 100x ^ { 2} - 81) ( x ^ { 2} + 25) = 0#?
1 Answer
Dec 13, 2017
Explanation:
#"equate each of the factors to zero and solve for x"#
#2x=0rArrx=0#
#100x^2-81=0larrcolor(blue)"is a difference of squares"#
#•color(white)(x)a^2-b^2=(a-b)(a+b)#
#rArr100x^2-81=(10x-9)(10x+9)=0#
#10x-9=0rArrx=9/10#
#10x+9=0rArrx=-9/10#
#x^2+25=0#
#rArrx^2=-25larrcolor(blue)"has no real solutions"#
#rArrx=+-5i#
#"the solutions are "x=0,x=+-9/10,x=+-5i#
