2. 2x + 5y = x + 3y = 22
How can we solve this equation by elimination?

4. You Try…Solve by elimination
–2x + 15y = –32 7x – 5y = 17 3(7x – 5y = 17) 21x – 15y = 51
–2x + 15y = –32 21x – 15y = 51 19x = x = 1
7x – 5y = 17
7(1) – 5y = 17
7 –5y = 17
–5y = 10
–5 –5
y = –2
(1, –2)

8. 15x + 3y = 9 10x + 7y = -4
7(15x + 3y = 9) 3(10x + 7y = –4) 105x + 21y = 63 30x + 21y = x – 21y = 12 75x = x = 1
15x + 3y = 9 15(1) + 3y = y = y = y = -2
(1,-2)

9. Homework