There are 30 flowers. Some have 3 petals and some have 4 petals.All the flowers together have 102 petals. How many flowers have 4 petals?

Guest Aug 31, 2020

#1**+1 **

Let x be the number of flowers with 3 petals and 30-x the number of flowers with 4 petals. We form an equation:

3x+4(30-x)=102

3x+120-4x=102

-x+120=102

-x=-18

x=18 3 petal flowers,

So there are 30-18=**12 4 petal flowers.**

gwenspooner85 Aug 31, 2020

#2**+1 **

You never know when you will need system of equation!

The the number of 3-petal flowers be x, and the number of 4-petal flowers be y.

from here, we know that:

x + y = 30

3x + 4y = 102

Using substitution, we see that:

x = 30 - y

3(30 - y) + 4y = 102

90 - 3y + 4y = 102

90 + y = 102

y = **12**

Here are some 4 pétaled flowers for you:

:)

ilorty Aug 31, 2020