When
を活（い）かす is partnered with a noun, it shows that (A) is something that is being made good use of, or leveraged. This can be in relation to skills, experiences, attributes, and many other things.
This grammar point may appear either in the form of the う-Verb
活（い）かす ‘to enliven’ or
生（い）かす ‘to keep alive’, with very little change in nuance. However,
活（い）かす tends to appear far more frequently, as the focus of this kanji is less in relation to the preservation of life, and more on just ‘making good use’ of something.
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このパソコンの機能（きのう）を十分（じゅうぶん）に活（い）かすのにはたくさんの知識（ちしき）が必要（ひつよう）だ。
You need to be very knowledgeable inorder to make use of all the features of this computer.
この失敗（しっぱい）を次（つぎ）に活（い）かしてみてください。
Please try to make use of this failure next time.
When linked to a (B) noun, in order to show that something ‘has’ been made good use of,
活（い）かす will appear in the past tense.
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私（わたし）のくせ毛（げ）を活（い）かした髪型（かみがた）にカットしてください。
Please give me a haircut that makes good use of my curly hair.
この料理（りょうり）は鯖（さば）の旨味（うまみ）を活（い）かした料理（りょうり）なので調味料（ちょうみりょう）はあまり使（つか）っていません。
This dish makes the most of the flavor of mackerel, so not much seasoning is used.
Fun-fact -
活（い）かす will often be used with adverbs of amount or quality, in order to highlight just how well (A) is being made good use of, or capitalized on. Examples include 十分（じゅううぶん）に ‘adaquately’, 有効（ゆうこう）に ‘effectively’, 最大限（さいだいげん）に ‘to the fullest’, and similar words.
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私（わたし）は仕事（しごと）で日本語（にほんご）を十分（じゅうぶん）に活（い）かせるかが心配（しんぱい）です。
I am concerned about my ability to fully make use of my Japanese at work.
勉強（べんきょう）が出来（でき）る時間（じかん）は限（かぎ）られている為（ため）、時間（じかん）を有効（ゆうこう）に活（い）かせるようにプランを立（た）ててから勉強（べんきょう）をするようにしています。
The time that I can study is limited, so in order to make good use of my time, I make sure to make a plan before I start studying.