Hey there!/¡Hola!
(3a + 4b) - (5a - 2b)
= 3a + 4b - 5a - 2b
COMBINE the LIKE TERMS/COMBINAR los TÉRMINOS LIKE
= (3a - 5a) - (4b - 2b)
= 3a - 5a - 4b - 2b
= -2a + 6b
Result/Resulta: -2a + 2b
Good luck on your assignment & enjoy your day!/¡Buena suerte en tu tarea y disfruta tu día!
~Amphitrite1040:)