Question

how do I solve this proportion?

Answer 1

Okay this should be simple. So take 10 times 3. Because those are diagnal to eachother. 10*3 = 30. Now take 30 divided by 7. 30/7 = 4.28 and rounded would be just 4.2. That's your answer! Hope i helped! 

Answer 2

$\frac{3}{x}=\frac{7}{10};\ \ \ \ D:x\neq0\\\\cross\ multiply:\\\\7\cdot x=3\cdot10\\\\7x=30\ \ \ \ /:7\\\\x=\frac{30}{7}\\\\x=4\frac{2}{7}$