Victory for the ACT Student Text 15e

230 • M ATH

SLOPE-INTERCEPT FORM OF A LINEAR EQUATION

11. A line includes the points (2,3) and (3,6). What is the equation of the line? A. y x 2 3 = − B. y x 3 3 = − C. y x 2 3 3 = − D. y x 3 3 = + E. y x 3 = − 12. Š‹…Š ‘ˆ –Š‡ ˆ‘ŽŽ‘™‹‰ ‹• –Š‡ ‡“—ƒ–‹‘ ˆ‘” –Š‡ Ž‹‡ ™‹–Š •Ž‘’‡ ‘ˆ ʹ –Šƒ– ‹…Ž—†‡• point (0,2)? F. y x 1 = − G. y x 2 1 = − H. y x 2 2 = − J. y x 2 2 = + K. y x 1 = + 13. Š‹…Š ‘ˆ –Š‡ ˆ‘ŽŽ‘™‹‰ ‹• –Š‡ ‡“—ƒ–‹‘ for the line that includes points ( , )1 1 and (7,5)? A. y x 2 2 = + B. y x 2 2 3 = + C. y x 2 3 2 = + D. y x 2 2 3 = + E. y x 2 2 = +

14. If the graph of a line includes the points ȋʹǡͶȌ ƒ† ȋͺǡ͹Ȍǡ ™Šƒ– ‹• –Š‡ y -intercept of the line? F. 6 G. 4 H. 3 J. 1 K. 3 15. If the slope and y -intercept of a line are –2 and 3, respectively, then the line passes –Š”‘—‰Š ™Š‹…Š ‘ˆ –Š‡ ˆ‘ŽŽ‘™‹‰ ’‘‹–•ǫ A. ( , ) 5 10 B. ( , ) 5 10 C. ( , )2 3 D. ( , )3 4 E. ( , ) 4 5

Throwback to Math Class The slope- intercept form of a linear equation is y mx b + = ǡ ™Š‡”‡ m is the slope of the line and b is the y -intercept of the line. Test the Test As a last resort, you can use test-the-test by plugging both points into every ƒ•™‡”…Š‘‹…‡Ǥ Š‡ …‘””‡…– ƒ•™‡” choice is the ‘‡ ™Š‡”‡ „‘–Š points satisfy the equation. This should be a last resort because it ™‹ŽŽ ”‡“—‹”‡ ‘”‡ computation –Šƒ ϐ‹†‹‰ –Š‡ equation directly.