JSFiddle - React, Tailwind, and code Playground
HTML
<input type="checkbox" id="readTerms2" name="agree"> <input type="checkbox" id="readTerms" name="agree"> <label for="agree">By checking the box you agree to the <a href="/terms" target="_blank">Terms & Conditions</a>.</label>
<input id="submitBusiness" class="btn positive iconCheck right" type="submit" name="create" value="Submit" disabled="disabled" />
JavaScript
$('#readTerms').change( function() {
$('#submitBusiness').attr('disabled', !this.checked);
});