The Seven of Wands is a card of defense and opposition, as we find ourselves "under siege". Criticism and attacks from other people are likely to occur when this card comes up. It's also a card of resistance, so whenever it appears in a spread, the natural flow is blocked. The Five of Pentacles represents struggles that come from financial obligations, loss and material concerns in general. It also shows differences and incompatibilities that cause disruptions.
To understand the elemental relationships between the cards, we should always take into account their actual meaning. The elements of the cards are Fire (Seven of Wands) and Earth (Five of Pentacles). The blending of Fire and Earth results in a neutral combination, which could be either negative or positive. However, since both cards bear some challenging energies, the manifestation of this combination would show a rather difficult situation. The Fire of the Seven of Wands will probably fail to energize the Earth of the Five of Pentacles in a way that will produce positive results, since there's so much resistance.