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Home > A2C > Chapter Ch9 > Lesson 9.3.2 > Problem 9-151

9-151.
  1. Where do the graphs below intersect? You should be able to do these without a graphing calculator. Homework Help ✎
    Without using a calculator icon

    1. 2x + y = 10
      x + y = 25

    2. 2x + y = 10
      x2 + y2 = 25

Multiply the second equation by −1 and add the two equations together.

2x + y = 10
xy = −25

x = −15

Use the x-value to calculate the y.

y − 15 = 25

y = 40

(−15, 40)

Solve the first equation for y and substitute it into the second.