JSFiddle - React, Tailwind, and code Playground

HTML

<div class="row">
  <div class="leftcol">
    <p>
    dsdsfnsdk s fsdjf ksf ksj sjfkshkfsh kshf ksjdhf ksjhf kjshdfk hksj fkshkf jsdhf kjsh kshf kjshkh ksdhf ksjhf kshf kjsf skfkhkhksh fk
    </p>
    <img src="http://placehold.it/400x200">

  </div>
  <div class="fixedwidth">

    sdfdsfs ds fs

  </div>
</div>

CSS

.row {
  display: flex;
  background-color: red;
  padding: 2px;
}

.leftcol {
  flex: 1 1 auto;
  background-color: #ddd;
}

.fixedwidth {
  background-color: #eee;
  width: 200px;
  flex: 0 0 auto;
}

img {
  width: 100%;
  max-width: 400px;
}