In a system of equations, one pair must make both equations true. If one equation already fixes a variable, use it to predict one coordinate. Then type both equations in Desmos and click their intersection. In , comes first and comes second. Reversing them can make the pair fail an equation.
Hints
- Hint 1
The equation fixes one coordinate of the solution. An ordered pair writes the coordinates as . Which position must contain ?
- Hint 2
Each equation graphs as a line. The intersection is where the lines meet, so its coordinates make both equations true. Type each equation as written and click that point.
Step-by-step
Read the intersection in Desmos
Step 1Place the known coordinate
The equation fixes at , so every solution to the whole system has as its second coordinate. The first coordinate, , is still unknown.
- Step 2
Find the point that satisfies both equations
Type and on separate lines in Desmos. Click their intersection; Desmos shows . A point on both lines makes both equations true, so the solution is . Choice D.