Answer:
To multiply two fractions, we multiply the numerators to get the new numerator and multiply the denominators to get the new denominator. However, we are taught that when faced with a problem such as 3⁄5 ÷ 4⁄7, we should invert the second fraction and multiply.
Answer:

Step-by-step explanation:

Let X = pounds of Bermuda grass needed.
(20 pounds bahia grass x $6.30) + ( X x $3.65) = (20 +X) x $4.90
Simplify:
126 + 3.65X = 98 + 4.90X
Subtract 3.65X from each side:
126 = 98 + 1.25X
Subtract 98 from each side:
28 = 1.25X
Divide both sides by 1.25
X = 28 / 1.25
X = 22.4 pounds required.