SAT Question cb58833c: Linear Equations In Two Variables answer and explanation with Desmos solution

The $y$-coordinate of the $x$-intercept is $0$, so $0$ can be substituted for $y$, giving $\frac{4}{5}x+\frac{1}{3}\times 0=1$. This simplifies to $\frac{4}{5}x=1$. Multiplying both sides of $\frac{4}{5}x=1$ by $5$ gives $4x=5$. Dividing both sides of $4x=5$ by $4$ gives $x=\frac{5}{4}$, which is equivalent to $1.25$. Note that 5/4, 1.25, and 1.250 are examples of ways to enter a correct answer.