Answer: Let x be the amount of yarn needed for a single crochet stitch in inches.
Then the amount of yarn needed for a double crochet stitch is (2x - 1/2) inches.
And the amount of yarn needed for a triple crochet stitch is (3x - 1) inches.
To find the total amount of yarn needed for the scarf, we can use the following expression:
800x + 400(2x - 1/2) + 200(3x - 1)
Simplifying this expression, we get:
800x + 800x - 200 + 600x - 200
= 2000x - 400
Therefore, the expression that represents the amount of yarn Jada needs to crochet a scarf that includes 800 single crochet stitches, 400 double crochet stitches, and 200 triple crochet stitches is 2000x - 400, where x is the amount of yarn needed for a single crochet stitch in inches.
Step-by-step explanation: