Donata bought 4 lemons and 4 plums at the local supermarket for a total of $ 21.60. dan bought 11 lemons and 6 plums at the same store for a total of $40.90 how much does one lemon cost. . pleass

you must establish a equation system  with the information given , 4x numbers of limon , where x represent the cost of every lemon and 4y numbers of plums , where y represents the cost of plumsnow  the equation system is 1) 4x+ 4y = 21,60 and 2) 11x+ 6y = 40.29of the equation 1 you must obtain the value of x, 4x = 21.60+4y ⇒x=21.60/4+4y/4⇒x= 5.4+ynow with the value of x , it is substitute in the equation 2)   11(5.4+y) + 6y = 40.29 , ⇒ 59.4 + 11y + 6y = 40.29 ⇒  17y = 40.29-59.4⇒ y = -19,11/7⇒ y = -2.73the value of y is substitute in the equation 1) x = 5.4 + ( -2,73)⇒ x= 2,67,  where ,the price of every lemon is $ 2,67

X^4 + 36x^2 = x^2(x^2+36)= x*x*(x+6i)(x-6i) mark me brainliest