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Which value of y makes the inequality 3y^2+2(y-5)>8 true

A y=0
B y= -1
C y= -2
D y= -3

User Dom Free
by
7.9k points

2 Answers

13 votes

Answer:

D

Explanation:

User LazyTarget
by
7.5k points
8 votes

Answer:

Conclusion:

As y = -3 MAKES the inequality TRUE.

Therefore, option D i.e. y = -3 is true.

Explanation:

Given the inequality

3y² + 2(y - 5) > 8

For y = 0

substitute y = 0 in the inequality

3y² + 2(y - 5) > 8

3(0)² + 2(0 - 5) > 8

3(0) + 2(-5) > 8

0 - 10 > 8

-10 > 8

FALSE!

-10 can not be greater than 8.

Hence, y = 0 does not make the inequality true.

For y = -1

substitute y = -1 in the inequality

3y² + 2(y - 5) > 8

3(-1)² + 2(-1 - 5) > 8

3(1) + 2(-6) > 8

3 - 12 > 8

-9 > 8

FALSE!

-9 can not be greater than 8.

Hence, y = 1 does not make the inequality true.

For y = -2

substitute y = -2 in the inequality

3y² + 2(y - 5) > 8

3(-2)² + 2(-2 - 5) > 8

3(4) + 2(-7) > 8

12 - 14 > 8

-2 > 8

FALSE!

-2 can not be greater than 8.

Hence, y = -2 does not make the inequality true.

For y = -3

substitute y = -3 in the inequality

3y² + 2(y - 5) > 8

3(-3)² + 2(-3 - 5) > 8

3(9) + 2(-8) > 8

27 - 16 > 8

11 > 8

TRUE!

11 is indeed greater than 8.

Hence, y = -3 MAKES the inequality TRUE.

Conclusion:

As y = -3 MAKES the inequality TRUE.

Therefore, option D i.e. y = -3 is true.

User Nghia Nguyen
by
8.3k points

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