## Algebra: A Combined Approach (4th Edition)

y = 2x + 3 5y - 7x = 18 Substitute y = 2x + 3 to the second equation. 5 ( 2x + 3 ) - 7x = 18 10x + 15 - 7x = 18 (use the distributive property simplify) 3x + 15 = 18 ( simplify ) 3x + 15 - 15 = 18 - 15 3x = 3 ( divide both sides by 3 ) x = 1 Substitute x = 1 to the first equation. y = 2 $\times1 + 3$ y = 5