Can y o u e l i m i n a t e
choices?
Ye s. Th e b o u n d a r y l i n e
is solid and the region
below it is shaded, so
you know t he i nequal it y
symb o l m u st b e s. Yo u
can el i mi nat e choi ces
C a n d D.Writing an Inequality From a GraphMultiple Choice Which inequality represents the graph at the right?
< 3 D y =£ 2 x + l GD y > 2x + l
CD y =£ x +^1 dD y <^2 x + l
The slope of the line is 2 and the y-intercept is 1, so the equation of the
boundary line is y = 2x + 1. The boundary line is solid, so the inequality
symbol is either < or s. The symbol must be < , because the region
below the boundary line is shaded. The inequality is y < 2x + 1.
The correct answer is A.^ Got It? 5. You are writing an inequality from a graph. The boundary line is dashed
and has slope | and y-intercept —2. The area above the line is shaded. What
inequality should you write?Lesso n Ch eck
Do yo u k n o w HOW?- Is (-1 ,4 ) a solution of the inequality y < 2x + 5?
Graph each linear inequality.- y<-2x + 3 3. x< — 1
- What is an inequality that
represents the graph at
the right?
*>L yif
I^0 >x
s'L_________ MATHEMATICAL
Do yo u UNDERSTAND? {g jjl PRA CTI CES- Vo cab u lary How is a linear inequality in two
variables like a linear equation in two variables?
How are they different? - Writing To graph the inequality y < \x + 3, do you
shade above or below the boundary line? Explain. - Reasoning Write an inequality that describes the
region of the coordinate plane not included in the
graph of y < 5x + 1.
Pr act i ce an d Pr o b l em - So l v i n g Ex er ci ses
.1^ 1 Pr act i ce
MATHEMATICAL
PRA CTI CESDetermine whether the ordered pair is a solution of the linear inequality. Se e Pr o b l e m t.- y <-2x + 1; (2,2) 9 .x < 2 ; (-1 ,0 ) 10. y > 3x - 2; (0, 0)
- y>x- 1; (0,1) 12. y> —|x + 4;(0, 0) 13. 3y > 5 x - 12; ( - 6 ,1)
Graph each linear inequality. Se e Pr o b l e m 2.- y<x-l 15. y>3x-2 16. y < —4x —^1 17. y >^2 x —^6
- y<5x-5 19. y<|x-3 20. y>-3x^21 .y>-x
I J2 SSSEE3 3 EEI S2 3 P LLesson 6-5 Linear Inequalities^397
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