A system of linear equations gives two rules for the same and . Graph both equations as written in Desmos, then click their intersection to find the values that satisfy both. Use those values to calculate the expression the question asks for. One coordinate or a given difference is not the sum.
Hints
- Hint 1
An intersection is where two graphed lines meet. Its coordinates satisfy both equations at once, so you can type each equation into Desmos as written without solving either one for .
- Hint 2
An ordered pair lists first and second. After you click the intersection, match each coordinate to its letter. The question asks for a sum, not either coordinate alone.
Step-by-step
Graph the system in Desmos
Step 1Graph both equations
Type and on separate Desmos lines. Desmos draws two lines that cross. Their intersection, the point where they meet, satisfies both equations.
- Step 2
Read the solution
Click the intersection. Desmos labels it , so the ordered pair gives first and second. Neither coordinate alone is the requested sum.
- Step 3
Find the sum
Type . Desmos prints , so the requested sum is . Choice D.