
Multiply both sides by 3

Simplify the numerators

Multiply both sides by 6

Simplify the numerator

Multiply both sides by x
12x - 18 = 15x Subtract 12x from both sides
-18 = 3x Divide both sides by 3
-6 = x Switch the sides to make it easier to read
x = -6
Check your answer by plugging -6 in for the x in the original problem:

Plug in -6 for x

Change

to

so all denominators are the same

Change

to

for easier work

Subtract the numerators (4 - (-1) )

=

So,
x = -6 .
Answer:

STEP BY STEP EXPLANATION

To make
a perfect square we should add 
She needs 5 cups of flour and 3 cups of sugar.
3 reds in the 10 remaining cards
so that is 30% are red