(2-3y)(2+3y) = (9y-2)(2-y)
4+6y-6y-9y² = 18y-9y²-4+2y
-9y²+9y²-18y-2y = -4-4
-20y = -8
20y = 8
y = 8÷20
y = 0,4
(2-3y)(2+3y) = (9y-2)(2-y)
4+6y-6y-9y² = 18y-9y²-4+2y
-9y²+9y²-18y-2y = -4-4
-20y = -8
20y = 8
y = 8÷20
y = 0,4