Question

What is T In the equation 3/7+t=20/21

Answer 1

Answer:

$\large\boxed{t=\dfrac{11}{21}}$

Step-by-step explanation:

$\dfrac{3}{7}+t=\dfrac{20}{21}\qquad\text{subtract}\ \dfrac{3}{7}\ \text{from both sides}\\\\\dfrac{3}{7}-\dfrac{3}{7}+t=\dfrac{20}{21}-\dfrac{3}{7}\qquad\text{LCD(7, 21)=21}\\\\t=\dfrac{20}{21}-\dfrac{3\cdot3}{7\cdot3}\\\\t=\dfrac{20}{21}-\dfrac{9}{21}\\\\t=\dfrac{20-9}{21}\\\\t=\dfrac{11}{21}$