Composer require-dev problems

Question

i have installed developer mode on windows at work, and i have a lot problems with installing some programs/features that i need to run project. One of problems is when i run composer install or composer install --no-plugins --no-scripts, it always give me this errors.

    Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Installation request for dompdf/dompdf v0.8.2 -> satisfiable by dompdf/dompdf[v0.8.2].
    - dompdf/dompdf v0.8.2 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
  Problem 2
    - Installation request for erusev/parsedown 1.7.1 -> satisfiable by erusev/parsedown[1.7.1].
    - erusev/parsedown 1.7.1 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
  Problem 3
    - Installation request for laravel/framework v5.5.40 -> satisfiable by laravel/framework[v5.5.40].
    - laravel/framework v5.5.40 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
  Problem 4
    - Installation request for league/csv 8.2.3 -> satisfiable by league/csv[8.2.3].
    - league/csv 8.2.3 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
  Problem 5
    - Installation request for teamtnt/tntsearch v1.3.1 -> satisfiable by teamtnt/tntsearch[v1.3.1].
    - teamtnt/tntsearch v1.3.1 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
  Problem 6
    - Installation request for facebook/webdriver 1.3.0 -> satisfiable by facebook/webdriver[1.3.0].
    - facebook/webdriver 1.3.0 requires ext-curl * -> the requested PHP extension curl is missing from your system.
  Problem 7
    - Installation request for phpunit/phpunit 6.5.8 -> satisfiable by phpunit/phpunit[6.5.8].
    - phpunit/phpunit 6.5.8 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
  Problem 8
    - dompdf/dompdf v0.8.2 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
    - barryvdh/laravel-dompdf v0.8.2 requires dompdf/dompdf ^0.8 -> satisfiable by dompdf/dompdf[v0.8.2].
    - Installation request for barryvdh/laravel-dompdf v0.8.2 -> satisfiable by barryvdh/laravel-dompdf[v0.8.2].

  To enable extensions, verify that they are enabled in those .ini files:
    - /etc/php/7.0/cli/php.ini
    - /etc/php/7.0/cli/conf.d/10-opcache.ini
    - /etc/php/7.0/cli/conf.d/10-pdo.ini
    - /etc/php/7.0/cli/conf.d/15-xml.ini
    - /etc/php/7.0/cli/conf.d/20-calendar.ini
    - /etc/php/7.0/cli/conf.d/20-ctype.ini
    - /etc/php/7.0/cli/conf.d/20-dom.ini
    - /etc/php/7.0/cli/conf.d/20-exif.ini
    - /etc/php/7.0/cli/conf.d/20-fileinfo.ini
    - /etc/php/7.0/cli/conf.d/20-ftp.ini
    - /etc/php/7.0/cli/conf.d/20-gd.ini
    - /etc/php/7.0/cli/conf.d/20-gettext.ini
    - /etc/php/7.0/cli/conf.d/20-iconv.ini
    - /etc/php/7.0/cli/conf.d/20-intl.ini
    - /etc/php/7.0/cli/conf.d/20-json.ini
    - /etc/php/7.0/cli/conf.d/20-phar.ini
    - /etc/php/7.0/cli/conf.d/20-posix.ini
    - /etc/php/7.0/cli/conf.d/20-readline.ini
    - /etc/php/7.0/cli/conf.d/20-shmop.ini
    - /etc/php/7.0/cli/conf.d/20-simplexml.ini
    - /etc/php/7.0/cli/conf.d/20-sockets.ini
    - /etc/php/7.0/cli/conf.d/20-sysvmsg.ini
    - /etc/php/7.0/cli/conf.d/20-sysvsem.ini
    - /etc/php/7.0/cli/conf.d/20-sysvshm.ini
    - /etc/php/7.0/cli/conf.d/20-tokenizer.ini
    - /etc/php/7.0/cli/conf.d/20-wddx.ini
    - /etc/php/7.0/cli/conf.d/20-xmlreader.ini
    - /etc/php/7.0/cli/conf.d/20-xmlwriter.ini
    - /etc/php/7.0/cli/conf.d/20-xsl.ini
  You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.

I have installed PHP command php -v

PHP 7.0.30-0ubuntu0.16.04.1 (cli) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2017 Zend Technologies
    with Zend OPcache v7.0.30-0ubuntu0.16.04.1, Copyright (c) 1999-2017, by Zend Technologies

Answer 1

The solution for this error is installation of these two packages:

$sudo apt-get install php-mbstring 
$sudo apt-get install php-xml