A zero-product equation has factors multiplied together to make . In Desmos, graph the product and ; each intersection’s -coordinate is a solution. Find all the solutions before applying least positive. The leftmost solution might be negative, and another positive solution might be too large.
Hints
- Hint 1
A factor is one expression being multiplied. If any factor is , the whole product is . On a graph of the product, where would its height be zero?
- Hint 2
An -intercept is where a graph reaches height . Read the -coordinate at each intercept, then compare only the coordinates greater than .
Step-by-step
Graph the product and compare its solutions
Step 1Connect solutions to the graph
The given product equals , so a value of solves the equation if it makes the product . On the product’s graph, that happens at an -intercept, where the graph reaches height .
- Step 2
Read every solution, then choose
Type and in Desmos. Click their intersections: Desmos shows , , and . The -coordinates are the solutions. is negative, and , so the least positive solution is . Choice B.