<prompt> Mstari hupitia vekta tofauti mathbfa na mathbfb. Kisha kwa thamani fulani ya k, vekta.k mathbfa frac34 mathbfblazima pia ilale kwenye mstari. Tafuta k.  <response>: Mstari unaopita mathbfa na mathbfb unaweza kuainishwa namathbfa t mathbfb - mathbfa.Kuchukua t frac34, tunapatamathbfa frac34 mathbfb - mathbfa frac14 mathbfa frac34 4 mathbfb.Hivyo, k frac14. 