<h2>(1)</h2><h2> =(a+b)(3c-d)</h2><h2> =a(3c-d)+b(3c-d)</h2><h2> =3ac-ad+3bc-bd</h2>
<h2>(2)</h2><h2> =(a-b)(c+2d)</h2><h2> =a(c+2d)-b(c+2d)</h2><h2> =ac+2ad-bc-2bd</h2>
<h2>(3)</h2><h2> =(a-b)(c-2d)</h2><h2> =a(c-2d)-b(c-2d)</h2><h2> =ac-2ad-bc+2bd</h2>
<h2>(4)</h2><h2> =(2a+b)(c-3d)</h2><h2> =2a(c-3d)+b(c-3d)</h2><h2> =2ac-6ad+bc-3bd</h2>
Answer:
14 more flower would bloom if 21 more tulip bulb is planted.
Step-by-step explanation:
Given ratio for tulip bulbs and flowers is 15:10.
Now, finding number of flower to bloom if 21 tulip bulb are planted.
Assume if 21 tulip bulbs are planted then number of flower would bloom be"x"
ratio given: 
Cross multiplying the ratio to get:
⇒x= 
∴
Hence, 14 flowers would bloom if 21 tulip bulb are planted.
If total tulip bulb is
, then
would bloom.
That is why you have an education go to school and learn your anwer.