BG 2.42-43: Those with limited understanding, get attracted to the flowery words of the Vedas, which advocate ostentatious rituals for elevation to the celestial abodes, and presume no higher principle is described in them. They glorify only those portions of the Vedas that please their senses, and perform pompous ritualistic ceremonies for attaining high birth, opulence, sensual enjoyment, and elevation to the heavenly planets.
There are many verses that oppose vedas in gita.
Like
O Humans, only by performing noble and selfless deeds one should wish to live for hundred years. As you are involved in noble deeds, your mind will be purified and you will be no more attracted towards evil. This results in the increment in your knowledge, age and other good qualities. (Yajurveda 40/2)
O Agni, we adore you. Keep the sinners away from us. Take us away from path of destruction to the path of dharma so that we can enjoy through science, knowledge and wealth. (Yajurveda 40/16)
Now gita
BG 2.47: You have a right to perform your prescribed duties, but you are not entitled to the fruits of your actions. Never consider yourself to be the cause of the results of your activities, nor be attached to inaction.
BG 5.12: Offering the results of all activities to God, the karm yogis attain everlasting peace. Whereas those who, being impelled by their desires, work with a selfish motive become entangled because they are attached to the fruits of their actions.
Why it looks like bhagavad gita is opposing vedas.
