Hey there!
35/40 = 7/x
Cross Multiply the fraction
35(x) = (7)(40)
→ 35x = 280
DIVIDE 35 to BOTH SIDES
35x/35 = 280/35
CANCEL out: 35/35 because that gives you 1
KEEP: 280/35 because that helps solve for the x-value
→ x = 280/35
x = 8
Therefore, your answer is most likely: 8 (Option B)
Good luck on your assignment and enjoy your day!
~Amphitrite1040:)