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 plums
now the equation system is 1) 4x+ 4y = 21,60 and 2) 11x+ 6y = 40.29
of the equation 1 you must obtain the value of x, 4x = 21.60+4y ⇒x=21.60/4+4y/4⇒x= 5.4+y
now 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 = -2.73
the 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