40,0 square feet because I’m smart
Answer:
E = \frac{25M}{L}
Step-by-step explanation:
To solve this, we can multiple each side by E and then divide each side by L:

let x be the flour
now
or,(21/2)+x=42/3
or,(21+2x)/2=42/3
or, 3(21+2x)=42×2
or, 63+6x=84
or,6x=84-63
or, 6x =21
or, x=21/6
thus she need 21/6 cups of flour